Universal joints and methods of manufacture

ABSTRACT

An universal joint configured to transfer rotational movement from a first shaft to a second shaft at an angle and method of manufacturing the same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationNo. 62/478,489, filed Mar. 29, 2017, and titled “UNIVERSAL JOINT ANDMETHOD OF MANUFACTURE,” and further claims benefit of U.S. ProvisionalPatent Application No. 62/588,226, filed Nov. 17, 2017, and titled“X-JOINTS AND METHODS OF MANUFACTURE”. The entire disclosure of each ofthe above items is hereby made part of this specification as if setforth fully herein and incorporated by reference for all purposes, forall that it contains.

Any and all applications for which a foreign or domestic priority claimis identified in the Application Data Sheet as filed with the presentapplication are hereby incorporated by reference under 37 C.F.R. 1.57for all purposes and for all that they contain.

BACKGROUND Field

The present disclosure relates to x-joints and improved methods ofmanufacturing x-joints.

Description of the Related Art

Universal joints are often used for rotationally linking shafts that areoriented at a skewed angle relative to one another. One limitation ofexisting universal joints is failure under dynamic loading conditions.Dynamic loading of universal joints occurs both from changes in torquein the first shaft that are transmitted across the universal joint tothe second shaft and from changes in forces applied to individualcomponents of the universal joint as the joint rotates to maintain theskewed angle. Dynamic loading limits the use of structurally simpleuniversal joints to certain industrial tasks that could benefit from auniversal joint having a minimal moment of inertia. These include usesin drive trains, aircraft controls, automotive controls, manufacturing,machine tools, and other areas. Thus, it has become necessary to improvethe dynamic loading capacity of existing universal joints throughimproved manufacturing techniques and improved structures.

Universal joint designs can utilize sliding components to accommodatelarge axial loads (both tension and compression) from the shafts.Generally, a lubricant is used to reduce friction between the slidingcomponents of a universal joint and thereby reduce wear, minimizefriction and frictional losses, and extend service life of the variouscomponents of the joint and the joint overall. However, in someuniversal joints having an open configuration and/or close tolerances,maintaining adequate amounts of lubricant within the universal joint andbetween the sliding components of the universal joint can be difficultand/or require frequent re-application of the lubricant. This difficultycan also exist where operating conditions for the universal jointinclude high loading conditions, high rotations per minute (RPMs),unreliable or intermittent maintenance of the joint, dirty ordebris-filled operating conditions, extremely dry or wet operatingconditions, or extremely high or low temperature operating conditions.

SUMMARY OF THE TECHNOLOGY

A mechanical joint can include an increased dynamic loading capacity.Such an improvement can be obtained through the application of any ofthe methods of manufacture, or any combination of the methods ofmanufacture, described herein including: heat treatments, application ofvapor deposition coatings to specific surfaces of the joint,differential hardening of specific sliding components of the joint, andcryogenic hardening of specific sliding components of the joint.

A mechanical joint can include sliding components that can be designedto wear faster and more easily that certain sliding components. Forexample, certain sliding components can be manufactured more cheaply andeasily than other sliding components of the joints. Thus, one method ofmanufacture of a joint includes controlling wear on the slidingcomponents of the joint through differential hardening of the slidingcomponents. For example, in some embodiments of a joint, a first housingis made of a first steel. The first housing has a first notch with afirst inner cylindrical surface. A second housing is made of a secondsteel. The second housing has a second notch with a second innercylindrical surface. A follower or drive puck is made of a third steel.The follower has an outer cylindrical surface configured to mate withand slidingly engage the first inner cylindrical surface and the secondinner cylindrical surface. The joint is assembled by inserting the outercylindrical surface of the follower within the first notch of the firsthousing, inserting the outer cylindrical surface of the follower withinthe second notch of the second housing, and securing together the firstand second housing with the follower therebetween. A hardness of thefirst or second inner cylindrical surfaces of the first housing are atleast 2, 3, or 5 HRC above a hardness of the outer cylindrical surfaceof the follower. Thus, the more easily and/or more cheaply manufacturedsliding components can be designed to wear more quickly than othersliding components of the joint.

In another aspect, the first housing has a first inner spherical surfaceand the second housing has a second inner spherical surface. A pivotmember of a fourth steel has an outer spherical surface that mates withand slidingly engages the first inner spherical surface and the secondinner spherical surface. A hardness of the outer spherical surface is atleast 2, 3, or 5 HRC above a hardness of the first inner sphericalsurface.

In another aspect, the first, second, third and/or fourth steels aremade from SAE 4000 series steels or austenitic stainless steels.

In another aspect, a first vapor deposition coats the outer cylindricalsurface of the follower and/or a second vapor deposition coats the firstinner cylindrical surface of the first housing.

In another aspect, a first vapor deposition coats the outer sphericalsurface of the pivot member and/or a second vapor deposition coats thefirst inner spherical surface of the first housing.

Another method of manufacturing mechanical joint with a first housing, asecond housing, a follower is heat the first housing above a firstcritical temperature of a first steel, the first housing including thefirst steel. Maintain the first housing at or above the first criticaltemperature for a first austenizing time. The first austenizing time issufficient to convert a microstructure of the first steel to at least95% austenite. Quench the first housing below a martensitic starttemperature of the first steel at a first quench rate. The first quenchrate is sufficient to convert at least 83% of the microstructure of thefirst steel to martensite. Temper the first housing at a first tempertemperature below the first critical temperature of the first steel fora first temper time such that a hardness of a first inner cylindricalsurface of the first housing is at least 2, 3, or 5 HRC above a hardnessof an outer cylindrical surface of the follower. The outer cylindricalsurface is configured to mate with and slidingly engage the first innercylindrical surface.

In another aspect, heat the second housing above a second criticaltemperature of a second steel, the second housing comprising the secondsteel. Maintain the second housing at or above the second criticaltemperature for a second austenizing time. The second austenizing timeis sufficient to convert a microstructure of the second steel to atleast 95% austenite. Quench the second housing below a martensitic starttemperature of the second steel at a second quench rate. The secondquench rate is sufficient to convert at least 83% of the microstructureof the second steel to martensite. Temper the second housing at a secondtemper temperature below the second critical temperature of the secondsteel for a second temper time such that a hardness of a second innercylindrical surface of the second housing is at least 2, 3 or 5 HRCabove the hardness of the outer cylindrical surface of the follower.

In another aspect of the method, heat the follower above a thirdcritical temperature of a third steel, the follower comprising the thirdsteel. Maintain the follower at or above the third critical temperaturefor a third austenizing time. The third austenizing time is sufficientto convert a microstructure of the third steel to at least 95%austenite. Quench the follower below a martensitic start temperature ofthe third steel at a third quench rate. The third quench rate issufficient to convert at least 83% of the microstructure of the thirdsteel to martensite. Temper the follower at a third temper temperaturebelow the third critical temperature of the third steel for a thirdtemper time such that the hardness of the outer cylindrical surface ofthe follower is at least 2, 3 or 5 HRC below the hardness of the firstinner cylindrical surface of the first housing.

In another aspect of the method, the mechanical joint includes a pivotmember, heat the pivot member above a fourth critical temperature of afourth steel, the pivot member comprising the fourth steel. Maintain thepivot member at or above the fourth critical temperature for a fourthaustenizing time. The fourth austenizing time is sufficient to convert amicrostructure of the fourth steel to at least 95% austenite. Quench thepivot member below a martensitic start temperature of the fourth steelat a fourth quench rate. The fourth quench rate is sufficient to convertat least 83% of the microstructure of the fourth steel to martensite.Temper the pivot member at a fourth temper temperature below the fourthcritical temperature of the fourth steel for a fourth temper time suchthat a hardness of an outer spherical surface of the pivot member is atleast 2, 3 or 5 HRC above a hardness of a first inner spherical surfaceof the first housing. The outer spherical surface is configured to matewith and slidingly engage the first inner spherical surface.

In another aspect of the method, any of the steels is a SAE 4000 seriessteel.

In another aspect of the method, cryogenically harden the first housing,second housing, follower or pivot member below −115° C. for at least 24hours or below −184° C. for at least 12 hours.

In another aspect of the method, apply a first vapor deposition coatingonto at least one of the outer cylindrical surface of the follower, thefirst inner cylindrical surface of the first housing, the first innerspherical surface of the first housing, or the outer spherical surfaceof the pivot member.

In another aspect of the method, case-harden at least one of the firstinner cylindrical surface of the first housing, the outer cylindricalsurface of the follower, the first inner spherical surface of the firsthousing, or the outer spherical surface of the pivot member.

In another aspect of the method, shot peen at least one of the firstinner cylindrical surface of the first housing, the outer cylindricalsurface of the follower, the first inner spherical surface of the firsthousing, or the outer spherical surface of the pivot member.

In another method of manufacturing a mechanical joint with a firsthousing, a second housing, and a follower, heat a first component to afirst austenizing temperature, the first austenizing temperature isabove a first critical temperature of a first steel and above 600° C.,the first component comprising the first steel. Maintain the firstcomponent at or above the first austenizing temperature for a firstaustenizing time. The first austenizing time is sufficient to convert amicrostructure of the first steel to at least 95% austenite. Quench thefirst component to between 16° C. and 27° C. at a first quench rate, thequench leaving more than 3% of the microstructure of the first steel asretained austenite. Cryogenically treat the first component below −115°C. The first component is any of the first housing, second housing,follow or ball pivot.

In another aspect of the method, quench the first component to between16° C. and 27° C. leaves between 17% and 5% retained austenite andcryogenically treating the first component leaves less than 1% retainedaustenite.

In another aspect of the method, the first steel is an SAE 4000 seriessteel.

In another aspect of the method, apply a first vapor deposition coatingonto at least one of the outer cylindrical surface of the follower, thefirst inner cylindrical surface of the first housing, the first innerspherical surface of the first housing, or the outer spherical surfaceof the pivot member,

In another aspect of the method, case-harden the outer cylindricalsurface of the follower, the first inner cylindrical surface of thefirst housing, the first inner spherical surface of the first housing,or the outer spherical surface of the pivot member.

In another method of manufacturing a mechanical joint with a firsthousing, a second housing, a pivot member, and a follower, apply a firstvapor deposition coating to an outer cylindrical surface of thefollower; apply a second vapor deposition coating to an outer sphericalsurface of the pivot member; apply a third vapor deposition coating to afirst inner cylindrical surface and a first inner spherical surface ofthe first housing; apply a fourth vapor deposition coating to a secondinner cylindrical surface and a second inner spherical surface of thefirst housing; mount the follower within a first notch of the firsthousing with the outer cylindrical surface of the follower slidinglyengaged with the first inner cylindrical surface; mount the followerwithin a second notch of the second housing with the outer cylindricalsurface of the follower slidingly engaged with the second innercylindrical surface; mount the pivotal member within the first housingwith the outer spherical surface slidingly engaged with the first innerspherical surface; mount the pivotal member within the second housingwith the outer spherical surface slidingly engaged with the second innerspherical surface; assembling the first housing with the second housingsuch that the first housing and the second housing are fixedly engagedtogether and the follower is secured between the first housing and thesecond housing.

In another aspect of the method, the first vapor deposition coating isone of a physical vapor deposition coating comprising titanium nitrideor a chemical vapor deposition coating comprising titanium nitride.

In another aspect of the method, the physical vapor deposition coatingis applied in at least two layers to a depth between 2 and 5 microns.

In another aspect of the method, the physical vapor deposition coatingis applied in at least two layers to a depth between 5 and 10 microns.

In another aspect of the method, cryogenically treat the pivot memberbelow −115° C. for a bath time of at least 24 hours or below −184° C.for the bath time of at least 12 hours

In another aspect of the method, the pivot member is made from a firstaustenitic steel.

In another method of manufacturing a mechanical joint with a firsthousing, a second housing, a pivot member, and a follower, apply a firstphysical vapor deposition coating to an outer cylindrical surface of thefollower.

In another aspect of the method, apply a second physical vapordeposition coating to an outer spherical surface of the pivot member.

In another aspect of the method, apply a third physical vapor depositioncoating to a first inner cylindrical surface and a first inner sphericalsurface of the first housing.

In another aspect of the method, apply a fourth physical vapordeposition coating to a second inner cylindrical surface and a secondinner spherical surface of the first housing.

In another aspect of the method, the first, second, third, and fourthcoatings are applied simultaneously.

In another aspect of the method, the first vapor deposition coating is aphysical vapor deposition coating comprising titanium nitride.

In another aspect of the method, the physical vapor deposition coatingis applied in at least two layers to a depth between 2 and 5 microns.

In another aspect of the method, a hardness of the first physical vapordeposition coating is between 60 and 68 HRC.

In another aspect of the method, cryogenically treat the pivot memberbelow −115° C. for at least 24 hours below −184° C. for at least 12hours.

In another aspect of the method, the pivot member is made from a firstaustenitic steel.

In another aspect of the method, cryogenically treat the pivot memberbelow −115° C. for at least 24 hours and the pivot member is made from afirst austenitic steel.

In another method of manufacturing a mechanical joint with a firsthousing, a second housing and a pivot member, cryogenically treat thefirst housing below −115° C. for at least 24 hours below −184° C. for atleast 12 hours where the first housing is made from a first austeniticsteel.

One aspect of a mechanical joint includes an improved groove structureof a first housing. A first groove can include a first cylindricalcontact surface disposed in the inner surface of an outer casing on afirst side of a central cavity of the first housing. A second groove caninclude a second cylindrical contact surface disposed in the innersurface of the outer casing on a second side of the central cavity ofthe first housing. The first side can be opposite the second side. Afirst lip can include a first toroidal contact surface. The first lipcan extend inwardly toward the central cavity of the first housing at afirst open end. The first lip can be aligned with the first groove. Asecond lip can include a second toroidal contact surface. The second lipcan extend inwardly toward the central cavity at the first open end ofthe first housing. The second lip can be aligned with the second groove.A drive puck can include a first wing, a second wing, a circular outerperimeter, an outer toroidal contact surface and an inner slot disposedbetween the first wing and the second wing. The outer toroidal contactsurface can extend along the first and second wings and slidingly engagewithin the first and second grooves.

Another aspect of the joint includes a through-path defining a lubricantspace extending between a first end of a drive shaft and an inner wallof a central cavity at a first open end of a housing section. Thethrough-path can allow a lubricant to flow into and out of the centralcavity at the first open end of the first housing to provide lubricationto the components therein.

Another mechanical joint includes a 90°-100° joint. The joint cancomprise a housing with first and second ends, first and second drivepucks or drive pucks and first and second drive balls. The first andsecond drive balls can be rotatably coupled with the first and seconddrive pucks or pucks at opposite ends of the housing, respectively.First and second shafts can be coupled with the first and second driveballs. In this manner, the joint can transfer rotation between the firstand second shafts at an angle of up to about 90°-100°.

Another mechanical joint is a wrench attachment. The wrench attachmentcan comprise a housing with first and second ends and a rotationalsleeve rotatably coupled with the housing. The wrench attachment caninclude first and second drive pucks or pucks, a driver and a receivingsocket. The driver and receiving socket can be rotatably coupled withthe first and second drive pucks or pucks at opposite ends of thehousing, respectively. A wrench can be coupled with the receiving socketand a socket attachment can be coupled with the driver. A user can graspthe rotational sleeve and use the wrench to rotate the wrench attachmentwithin the rotational sleeve and to use the socket attachment.

In another aspect of the wrench attachment, two retention rings and tworetention slots, the retention slots are disposed on opposite ends ofthe housing, the retention rings configured to fit within the retentionslots. The rotational sleeve is retained on the housing between the tworetention rings. The rotational sleeve can include a contoured gripsurface.

Another mechanical joint for transferring rotational motion from a firstshaft to a second shaft includes a housing with an outer casing, acentral cavity, a first end and a second end. A first groove includes afirst contact surface and a second groove includes a second contactsurface. The first and second grooves are disposed on opposite sides ofthe central cavity. A first lip includes a third contact surface at thefirst end of the housing and the first lip aligns with the first groove.A second lip includes a fourth contact surface at the first end of thehousing. The second lip aligns with the second groove. A drive puckincludes a circular outer perimeter, an outer contact surface, and aninner slot. A drive shaft includes a first end and a second end, thefirst end pivotably coupled with the drive puck by a pin, the second endconfigured to couple with the first shaft. The drive puck is disposedwithin the first and second grooves, the outer contact surface slidinglyengaged with the first and second contact surfaces of the first andsecond grooves, respectively. The drive puck maintained within the firstand second grooves at the first end of the housing by the third andfourth contact surfaces of the first and second lips. The drive puckrotates within the first and second grooves in a first plane and thedrive shaft rotates about the pin in a second plane. The first plane isorthogonal to the second plane.

In another aspect of the mechanical joint, the housing includes a firsthousing component coupled with a second housing component. The firsthousing component includes an outer end and an inner end, the first andsecond grooves, and the first end of the housing. The second housingcomponent includes an outer end and an inner end, the second end of thehousing, and an aperture for coupling with the second shaft at the outerend. The inner ends of the first and second housing components arewelded together to form the housing with the drive puck disposed withinthe first and second grooves.

In another aspect of the mechanical joint, the second end of the driveshaft is a standard socket drive and the second end of the housingincludes a standard socket aperture.

In another aspect of the mechanical joint, the inner slot of the drivepuck includes a first flat side on the first wing and a second flat sideon the second wing. The first flat side is substantially parallel to thesecond flat side. The first aperture extends through the first andsecond flat sides. The first end of the drive shaft includes a firstplanar portion and a second planar portion. The first and second planarportions are disposed on opposite sides of the first end of the driveshaft. The second aperture extends through the first and second planarportions. The first and second planar portions slidingly engaged withthe first and second flat sides of the inner slot, respectively.

In another aspect of the mechanical joint, the housing includes a firsthousing component coupled with a second housing component. The firsthousing component includes an outer end and an inner end, the first andsecond grooves, and the first end of the housing. The second housingcomponent includes a third groove having a fifth contact surface, afourth groove having a sixth contact surface. The third and fourthgrooves disposed on opposite sides of the central cavity. A third lipincludes a seventh contact surface at the second end of the housing. Thethird lip aligned with the third groove. A fourth lip includes an eighthcontact surface at the second end of the housing. The fourth lip alignedwith the fourth groove. A second drive puck includes a circular outerperimeter, an outer contact surface, and an inner slot. A second driveshaft includes a first end and a second end. The first end pivotablycouples with the second drive puck by a second pin. The second endconfigured to couple with the second shaft. The second drive puck isdisposed within the third and fourth grooves and maintained therein bythe third and fourth lips. The inner end of the first housing componentis welded to the inner end of the second housing component.

In another aspect of the mechanical joint, the drive puck rotates in afirst plane and the second drive puck rotates in a second plane. Thefirst and second planes are orthogonal.

In another aspect of the mechanical joint, the outer contact surface ofthe drive puck is toroidal and the first and second lips each include atoroidal contact surface.

In another aspect of the mechanical joint, the outer contact surface ofthe drive puck is cylindrical and the first and second lips each includea cylindrical contact surface.

In another aspect of the mechanical joint, the first and second contactsurfaces of the first and second grooves, respectively, are cylindricaland convex.

Another mechanical joint for transferring rotational motion from a firstshaft to a second shaft includes a housing. The housing has a first endand a second end. A first channel is in the first end. A first drivepuck is in the first channel. The first drive puck includes a firstwing, a second wing, an inner slot, and a circular outer perimeterhaving an outer contact surface. A first drive shaft couples with thefirst drive puck. The first drive shaft includes a first end and asecond end. The first end pivotably coupled within the inner slot of thefirst drive puck by a first pin. The second end configured to couplewith the first shaft. A first cap ring includes a central opening andfirst and second channel segments. The first cap ring welded with thefirst end of the housing with the first drive puck disposed within thefirst channel and the first and second channel segments. The outercontact surface of the first drive puck slidingly engages with a bottomsurface of the first channel, and the second end of the first driveshaft extends through the central opening of the first cap ring. Thefirst drive shaft rotates in a first plane with respect to the housingabout the first pin and rotates in a second plane with respect to thehousing on the first puck.

In another aspect of the mechanical joint, the first end of the housingincludes a first concave spherical surface. The first cap ring includesfirst and second concave spherical segments, and the first end of thefirst drive shaft includes a first convex spherical surface. The firstend of the first drive shaft slidingly engaged with the first concavespherical surface and the first and second concave spherical segments.

In another aspect of the mechanical joint, the first and second wings ofthe first drive puck each include an inner planar surface forming theinner slot, and the first end of the first drive ball includes first andsecond opposite planar surfaces slidingly engaged with the inner planarsurfaces, respectively. The first pin extends through the first andsecond opposite planar surfaces and through the inner planar surfaces.

In another aspect of the mechanical joint, the first cap ring iselectron beam welded with the first end of the housing.

In another aspect of the mechanical joint, the second shaft is coupledwith the second end of the housing.

In another aspect of the mechanical joint, the second end of the housingincludes a second concave spherical surface. The second cap ringincludes first and second concave spherical segments, and the first endof the second drive shaft includes a second convex spherical surface.The first end of the second drive shaft slidingly engaged with thesecond concave spherical surface and the first and second concavespherical segments of the second cap ring.

In another aspect of the mechanical joint, the second drive shaftrotates about the second pin in the first plane and the second driveshaft rotates about the second drive puck in the second plane. The firstand second planes are orthogonal.

In another aspect of the mechanical joint, a through-path defining alubricant space extends through the housing to allow a lubricant to flowinto and out of a central cavity.

Another mechanical joint for transferring rotational motion from a firstshaft to a second shaft includes a housing. The housing has a first openend and a second end. A first drive puck is in the first open end. Thefirst drive puck includes a first wing, a second wing, an inner slot,and a circular outer perimeter having an outer contact surface. A firstdrive shaft couples with the first drive puck. The first drive shaftincludes a first end and a second end. The first end pivotably coupleswithin the inner slot of the first drive puck by a first pin. The secondend configured to couple with the first shaft. The first and secondwings of the first drive puck each include an inner planar surfaceforming the inner slot, and the first end of the first drive ballincludes first and second opposite planar surfaces slidingly engagedwith the inner planar surfaces, respectively. The first drive shaftrotates in a first plane with respect to the housing about the first pinand rotates in a second plane with respect to the housing on the firstpuck.

In another aspect of the mechanical joint, a hardness of the bottomsurface of the channel is at least 2, 3 or 5 HRC above a hardness of theouter contact surface of the drive puck.

In another aspect of the mechanical joint, the housing is cryogenicallyhardened below −115° C. for at least 24 hours below −184° C. for atleast 12 hours.

In another aspect of the mechanical joint, a physical vapor depositioncoating is applied to the outer contact surface of the drive puck.

In another aspect of the mechanical joint, the first cap ring iselectron beam welded with the first end of the housing.

In another aspect of the mechanical joint, the housing includes a firsthousing component made of steel and a second housing component made ofaluminum. The cap ring and the first housing component are mechanicallycoupled with the second housing component. The second housing componentincludes the channel.

In another aspect of the mechanical joint, first and second grooves arein the first open end of the housing on opposite sides of a centralcavity. First and second lips are at the first open end. The first andsecond lips align with the first and second grooves, respectively. Thedrive puck is slidingly engaged within the first and second grooves andmaintained within the first and second grooves at the first open end ofthe housing by the first and second lips.

In another aspect of the mechanical joint, third and fourth grooves arein the second end of the housing on opposite sides of the centralcavity. Third and fourth lips are at the second end of the housing. Thethird and fourth lips align with the third and fourth grooves,respectively. The second drive puck is slidingly engages within thethird and fourth grooves and maintained within the third and fourthgrooves at the second end of the housing by the third and fourth lips.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an embodiment of a joint.

FIG. 2 is an assembled view of the joint shown in FIG. 1.

FIG. 3 illustrates the joint shown in FIG. 2 in a second position duringrotation.

FIG. 4 illustrates the joint shown in FIG. 2 in a third position duringrotation.

FIG. 5 illustrates the joint shown in FIG. 2 in a fourth position duringrotation.

FIG. 6 is an exploded perspective view of a second embodiment of ajoint.

FIG. 7 is an assembled view of the joint in FIG. 6 in a first positionduring rotation.

FIG. 8 illustrates the joint shown in FIG. 7 in a second position duringrotation.

FIG. 9 illustrates the joint shown in FIG. 7 in a third position duringrotation.

FIG. 10 illustrates the joint shown in FIG. 7 in a fourth positionduring rotation.

FIG. 11 illustrates the joint shown in FIG. 7 in a fifth position duringrotation.

FIG. 12 illustrates a process of heat treating and cryogenicallytreating the sliding components of a joint when made from carbon steel.

FIG. 13 illustrates a process of cryogenically treating the slidingcomponents of a joint when made from austenitic stainless steel.

FIG. 14 illustrates a binary phase diagram of an unalloyediron-cementite system.

FIG. 15 illustrates a continuous cooling transformation (CCT) diagram ofa carbon steel.

FIG. 16 illustrates a martensite start (MS) temperature martensite final(MF) temperature chart for a carbon steel, up to 2.0 wt. % carbon.

FIG. 17 is a perspective view of a third embodiment of a joint.

FIG. 18 is a front view of the joint shown in FIG. 17.

FIG. 19 is an exploded perspective view of the joint shown in FIG. 17.

FIG. 20 is a perspective view of a housing of the joint shown in FIG.17.

FIG. 21A is a top view of the housing shown in FIG. 19.

FIG. 21B is a section view along the line A-A in FIG. 21A.

FIG. 22A is a top view of a cap ring of the joint shown in FIG. 17.

FIG. 22B is a section view along the line B1-B1 in FIG. 22B.

FIG. 22C is a section view along the line B2-B2 in FIG. 22B.

FIG. 23A is an end view of a drive puck of the joint shown in FIG. 17.

FIG. 23B is a side view of the drive puck of FIG. 23A.

FIG. 24A is a perspective view of a drive ball of the joint in FIG. 17.

FIG. 24B is a side view of the drive ball of FIG. 24A.

FIG. 24C is a section view along the line C-C in FIG. 24B.

FIG. 25A is a perspective view of a pin of the joint shown in FIG. 19.

FIG. 25B is a side view of the pin of FIG. 25A.

FIG. 25C is an end view of the pin of FIG. 25A.

FIG. 26 is a perspective view of a fourth embodiment a joint.

FIG. 27A is a side view of the joint in FIG. 26.

FIG. 27B is a section view along the line D1-D1 in FIG. 27A.

FIG. 28A is a side view of the joint in FIG. 26.

FIG. 28B is a front view of the joint in FIG. 26.

FIG. 29A is a section view along the line D2-D2 in FIG. 28B.

FIG. 29B is a side view of the joint in FIG. 26.

FIG. 30 is an exploded view of the joint in FIG. 26.

FIG. 31 is a perspective view of a fifth embodiment of a joint.

FIG. 32A is a side view of the joint of FIG. 31.

FIG. 32B is a top view of the joint of FIG. 31.

FIG. 33A is a perspective view of a first housing of the joint of FIG.31.

FIG. 33B is a top view of the first housing shown in FIG. 33A.

FIG. 34A is a section view along the line E-E in FIG. 33B.

FIG. 34B is a top view of the first housing shown in FIG. 33A.

FIG. 34C is a section view of the first housing shown in FIG. 34B.

FIG. 34D is a top view of the first housing shown in FIG. 33A.

FIG. 34E is a section view of the first housing shown in FIG. 34D.

FIG. 35A is a perspective view of a housing of the joint of FIG. 31.

FIG. 35B is a side view of the first and second housings of FIG. 35A.

FIG. 35C is a top view of the first and second housings of FIG. 35A.

FIG. 35D is a section view along the line F-F in FIG. 35B.

FIG. 36A is a perspective view of a drive puck of the joint of FIG. 31.

FIG. 36B is a top view of the drive puck of FIG. 36A.

FIG. 36C is a side view of the drive puck of FIG. 36A.

FIG. 36D is a back view of the drive puck of FIG. 36A.

FIG. 37A is a perspective view of a drive ball of the joint of FIG. 31.

FIG. 37B is a side view of the drive ball of FIG. 37A.

FIG. 37C is a section view along the line H-H in FIG. 37B.

FIG. 38A is a perspective view of a pin of the joint shown in FIG. 31.

FIG. 38B is an end view of the pin of FIG. 38A.

FIG. 38C is a side view of the pin of FIG. 38A.

FIG. 39 is an exploded assembly view of the joint shown in FIG. 31.

FIG. 40A is a top view of the assembly of the joint shown in FIG. 31.

FIG. 40B is a front view of the assembly of the joint shown in FIG. 40A.

FIG. 41 is a section view along the line J-J in FIG. 40B.

FIG. 42 is a section view along the line I-I in FIG. 40A.

FIG. 43 is a detail view at Detail K in FIG. 42.

FIG. 44 shows a sixth embodiment of a joint.

FIG. 45A is a side view of the joint shown in FIG. 44.

FIG. 45B is a front view of the joint of FIG. 45A.

FIG. 46A is a section view along the line L-L in FIG. 45B.

FIG. 46B is a side view of the joint shown in FIG. 44.

FIG. 47A is an end view of a housing of the joint shown in FIG. 44.

FIG. 47B is a side view of the housing of FIG. 47A.

FIG. 47C is a section view along the line M-M in FIG. 47A.

FIG. 48 is a partial exploded assembly view of the joint in FIG. 44.

FIG. 49A is a top view of the assembly of the joint shown in FIG. 44.

FIG. 49B is an end view of the joint shown in FIG. 49A.

FIG. 50A is a top view of the assembly of the joint shown in FIG. 44.

FIG. 50B is a side view of the joint shown in FIG. 50A.

FIG. 51 is a section view along the line N-N in FIG. 50A.

FIG. 52 is a section view along the line O-O in FIG. 50B.

FIG. 53 is a seventh embodiment of a joint as a socket wrench.

FIG. 54 is an exploded assembly view of the joint of FIG. 53.

FIG. 55 is a side view of the joint of FIG. 53.

FIG. 56 is a section view along the line P-P in FIG. 55.

FIG. 57 is a perspective view of an additional embodiment of a joint.

FIG. 58 is an exploded view of the joint of FIG. 57.

FIG. 59 is a perspective view of an additional embodiment of a joint.

FIG. 60 is an exploded view of the joint of FIG. 59.

FIG. 61 is a section view of the joint of FIG. 44 within a carrierbearing.

FIG. 62 is an exploded view of another embodiment of a joint.

FIG. 63 is an exploded view of another embodiment of a joint.

DETAILED DESCRIPTION

An aspect of the present disclosure is directed to devices and methodsthat effectively and efficiently allow for the transmission ofrotational forces via axially unaligned axes. The technologies hereinare described in the context of universal joints and have utility inthat context. However, the technologies disclosed also can be used inother contexts as well. Some embodiments also allow for axial loads,such as applied by thrusting, pulling, suspension, and the like, to bereadily accepted without interfering with operation of the device.

The detailed description set forth below is intended as a description ofcertain structural embodiments and methods of manufacturing of thejoints of the present disclosure, and is not intended to represent theonly form in which the technologies of the present disclosure can beconstructed or utilized. The description sets forth the functions andsequences of steps for constructing and operating the joints. It is tobe understood, however, that the same or equivalent functions andsequences can be accomplished by different embodiments and that they arealso intended to be encompassed within the scope of the presentdisclosure.

First and Second Embodiments of a Universal Joint

FIGS. 1-5 illustrate the structure of a first embodiment of a joint 10.The joint 10 is configured to transfer rotational movement from a firstshaft 12 to a second shaft 14 or vice versa. The joint 10 transfersrotational movement at a 1:1 ratio so that a unit amount of rotationfrom the first shaft 12 corresponds to a unit amount of rotation in thesecond shaft 14 even if the first and second shafts 12, 14 are at askewed angle. By way of example and not limitation, a 1° rotational turnof the first shaft 12 corresponds to a 1° rotational turn of the secondshaft 14. The first and second shafts 12, 14 rotate at the same speedthroughout the rotation. Accordingly, there is no binding between thefirst and second shafts 12, 14 during the rotational movement. Thesecond shaft 14 turns at the same speed as the first shaft 12.

With continued reference to FIGS. 1-5, the first and second shafts 12,14 can be skewed at an angle 17. By way of example and not limitation,such angle 17 can be between approximately 0° and 45°. The joint 10 cantransfer rotational movement from the first shaft 12 to the second shaft14 with a pair of followers (or bearings) 16, 18 that slide within thehousing 20 and are rotationally pinned to the pivot member 22. In someembodiments, the pivot member 22 has an outer spherical surface 52. Thefollowers 16, 18 help increasing the possible angle between the firstand second shafts 12, 14. Additionally, the joint 10 holds an axialload. By way of example and not limitation, opposing forces (e.g.,weight or pulling forces) can be applied to the first and second shafts12, 14.

According to one embodiment, the housing 20 has first and second halves24, 26. The first and second halves 24, 26 have inner spherical surfaces28, 30, respectively, that form a portion of a spherical cavity withinthe housing 20 (i.e., between the first and second halves 24, 26) inwhich the pivot member 22 is locked. The inner spherical surface 28 canterminate at an inner side 32 of the first half 24 of the housing 20.Similarly, the inner spherical surface 30 of the second half 26 of thehousing 20 can terminate at an inner side 34 of the second half 26 ofthe housing 20. This junction between the inner spherical surfaces 28,30 of the first and second halves 24, 26 define the equator of thespherical cavity that holds the pivot member 22. The thickness 36 of thefirst half 24 and the thickness 38 of the second half 26 can besufficient to hold the pivot member 22 within the inner cavity of thehousing 20. In other words, the pivot member 22 is sandwiched betweenthe first and second halves 24, 26 so that an axial load can be appliedto the first and second shafts 12, 14. The axial load can be in anyorientation including tension and compression.

The first and second halves 24, 26 can also have interior notches 40,42, 44 and 46. The inner surfaces of the notches 40-46 can have acylindrical configuration about axis 47. The axis 47 is parallel to theinner sides 32, 34 of the first and second halves 24, 26 of the housing20. Moreover, the axis 47 is transverse to a plane in which the notches40, 42 and 44, 46 reside. The notches 40-46 retain the followers 16, 18in place and allow the followers 16, 18 to rotate about the axis 47during rotational movement of the first and second shafts 12, 14.

The followers 16, 18 can have outer surfaces 16A, 18A that mate with theinner surfaces 40A, 42A, 44A, and 46A of the notches 40, 42, 44, 46,respectively. The outer surfaces 16A, 18A of the followers 16, 18 canalso define a circle or cylinder. Preferably, the outer surfaces 16A,18A of the followers 16, 18 can be cylindrical to match the cylindricalconfiguration of the inner surfaces 40A-46A of the notches 40-46. Theouter surfaces 16A, 18A of the followers 16, 18 slide on the innersurfaces 40A-46A of the notches 40-46 and do not rub excessively againstthe inner surfaces 40A-46A of the notches 40-46 which can cause thetransfer of rotation of movement between the first and second shafts 12,14 to be inefficient.

As described further below in other embodiments of the joint, thefollowers 16, 18 can be formed as an integral unit and operative todefine a generally C-shaped configuration. In such embodiments, and asopposed to having two opposed followers 16, 18 as shown, followers 16,18 can be interconnected to one another to form a continuous C-shapeleaving an opening through which shaft 14 can engage with splined recess23.

The inner surfaces 48, 50 of the followers 16, 18 can partially define asphere when the joint 10 is assembled. The inner surfaces 48, 50 matewith the outer spherical surface 52 of the pivot member 22. Duringrotation of the shafts 12, 14, the followers 16, 18 can pivot aboutpivot axis 54. Alternatively, the inner surfaces 48, 50 of the followers16, 18 can comprise flat surfaces and/or be slidingly engaged with flatareas on the outer surface of the pivot member located on opposite sidesof the pivot member around the pins 56, 58.

The pivot axis 54 can be defined by pins 56, 58 that extend outlaterally from the pivot member 22. The pins 56, 58 can be fabricated asa unitary structure to the pivot member 22. Alternatively, the pins 56,58 can be separate from the pivot member 22 and reside within therecesses 60, 62 formed in the pivot member 22. In this embodiment, thepins 56, 58 can be a pin 56 extending through a single recess 60 withinthe pivot member 22. The pins 56, 58 can also be disposed withincorresponding recesses 60, 62 of the first and second followers 16, 18.As a further alternative, the pins 56, 58 can be formed as a unitarystructure to the followers 16, 18 and the pins 56, 58 can protrudeinward and be received within matching recesses formed in the pivotmember 22. Accordingly, it can be readily understood and appreciated bythose skilled in the art that any of a variety of mechanisms can beutilized as to how first and second followers, 16, 18 can be maintainedin axial registry relative to pivot axis 54 and that the same can beaccomplished by any of the foregoing mechanisms, as well as anyadditional mechanism that enables a follower 16, 18 to releasablyinterconnect with the outer spherical surface 52 of the pivot member 22about pivot axis 54, whether it be through mechanisms formed upon thefollowers, 16, 18, the pivot member 22, or both.

The joint 10 can also have an O-ring 64 that is positioned between thefirst and second halves 24, 26 of the housing 20. The O-ring 64 canreside within the grooves formed within the inner sides 32, 34 of thefirst and second halves 24, 26. The O-rings 64 can serve to retaingrease or lubricants in the housing 20 during use. In some embodiments,a flexible sleeve can extend over the joint 10 and be secured around thefirst and second shafts 12, 14. This flexible sleeve can contain agrease or other lubricant.

The shafts 12, 14 are respectively secured to the housing 20 and thepivot member 22. One of the shafts 12, 14 can be secured to the housing20. The other one of the shafts 12, 14 can be secured to the pivotmember 22. In FIG. 2, the shaft 12 is shown as being fixedly secured tothe housing 20, whereas, the shaft 14 is shown as being fixedly securedto the pivot member 22. The shaft 12 can be secured to a housing mount66. The housing mount 66 can be attached to the first half of thehousing 20 by any means known in the art or developed in the future. Byway of example and not limitation, the housing mount 66 can be bolted,glued or welded to the first half 24 of the housing 20. Moreover, thefirst shaft 12 can have a fixed relationship to the housing mount 66.The second shaft 14 can be secured to the pivot member 22 to have afixed relationship thereto. The second shaft 14 can be splined andslidably or fixedly engage a splined recessed 23 of the pivot member 22.

The lateral side of the second half 26 of the housing 20 can define aconical surface 76. The conical surface 76 allows the angle 17 betweenthe first and second shafts 12, 14 to be increased to a greater degreecompared to forming the second half 26 without the conical surface 76.The second shaft 14 rides closely adjacent to the conical surface 76during rotational movement of the joint 10 when the angle 17 between thefirst and second shafts 12, 14 is at its maximum angle.

Referring now to FIGS. 2-5, operation of the joint 10 is shown. Theshafts 12, 14 are set to an angle 17. As the shaft 12 rotates as shownby the rotational arrow in FIG. 2, the shaft 12 rotates the housingmount 66. Since the housing mount 66 is secured to the housing 20,rotation of the shaft 12 also consequently rotates the housing 20.Rotational motion is transferred from the housing 20 to the followers16, 18 which are disposed within the notches 40-46 of the housing.During rotation, the followers 16, 18 slide within the notches 40-46.The follower 16 moves outward from the housing 20 by a degree, whereas,the follower 18 recedes into the housing 20. Rotational motion is alsotransferred to the pivot member 22 by way of pins 56, 58. The pins 56,58 are rotationally disposed within recesses 60, 62. The pins 56, 58 areconnected to the pivot member 22. The pivot member 22 transfersrotational motion to the second shaft 14 since the pivot member 22 isfixedly attached to the second shaft 14.

Between the followers 16, 18 and the pivot member 22, the pivot member22 pivots about pivot axis 54 in relation to the followers 16, 18.Between the housing 20 and the followers 16, 18, the followers 16, 18rotationally slide within the notches 40-46 formed in the housing 20about axis 47. Throughout rotational movement of the first shaft 12, (1)the followers 16, 18 can slide within the notches 40-46, and (2) thepivot member 22 pivots about the followers 16, 18. This is illustratedby the rotational sequence shown in FIGS. 2-5.

In the embodiment shown in FIGS. 1-5, the joint 10 has followers 16, 18that slide within the notches 40-46 of the first and second halves 24,26 of the housing 20. The followers 16, 18 distribute the load imposedby the pins 56, 58 to mitigate stress concentrations that the pins 56,58 can impose upon the inner surfaces of the notches 40-46. Moreover,the followers 16, 18 allow the first and second shafts 12, 14 to be setat a greater angle 17. However, it is also contemplated that the joint10 can also function without the followers 16, 18. During rotationalmovement of the shafts 12, 14, the pins 56, 58 can slide and rotate onthe inner surfaces of the notches 40-46. The angle 17 is limited to thepoint at which the pins 56, 58 would come out of the notches 40-46. Inthis regard, the followers 16, 18 allow the first and second shafts 12,14 to be set at a greater angle yet transmit rotational motion betweenthe first and second shafts.

It is also contemplated that two or more joints 10 can be secured toeach other in series. A second shaft of a first joint 10 can becoaxially aligned and attached to a first shaft of a second joint 10. Asecond shaft of the second joint 10 can be coaxially aligned andattached to a first shaft of a third joint 10. Rotation of the firstshaft of the first joint 10 is operative to rotate a second shaft of thethird joint 10. In this example, three joints 10 were connected to eachother to transmit rotational motion. Each of the first and second shaftsof the joints 10 can be at a skewed angle.

As described above, an aspect of some embodiments is the realizationthat the wear on the surfaces of some sliding components can beminimized and/or controlled and thereby the effective service life of ajoint can be extended and/or the dynamic loading capacity of the jointcan be increased. Such a configuration can be implemented in the joint10, depending on the desired wear properties of the sliding components.For example, in some embodiments, the followers 16, 18 (either alone oras an integral C-shaped unit) may be manufactured more cheaply and/orare easier to service and replace than the housing halves 24, 26. Thus,minimizing wear on the inner surfaces 40A-46A of one or both housinghalves 24, 26 can be an objective of the joint 10. To this end, in someembodiments of the joint 10, the inner surfaces 40A, 42A of the housinghalf 24 and/or the inner surfaces 44A, 46A of the housing half 24 canhave a hardness greater than a hardness of the outer surfaces 16A, 18Aof the followers 16, 18. In these embodiments, the inner surfaces 40A,42A of the housing half 24 and/or the inner surfaces 44A, 46A of thehousing half 24 are at least 2, 3, or 5 points harder than the outersurfaces 16A, 18A of the followers 16, 18 as measured on the RockwellHardness scale (HRC). For example, in some embodiments where the housing20 and the followers 16, 18 are made from steel, the hardness of theinner surfaces 44A, 46A is 44 HRC and the outer surfaces 16A, 18A have ahardness of 43, 42, or 39 HRC.

In other embodiments of the joint 10, the housing halves 24, 26 can bemanufactured more cheaply and/or are easier to service and replace thanfollowers 16, 18. Thus, minimizing wear on the outer surfaces of one orboth followers 16, 18 can be an objective of the joint 10. To this end,the inner surfaces 40A, 42A of the housing half 24 and/or the innersurfaces 44A, 46A of the housing half 24 can have a hardness less than ahardness of the outer surfaces 16A, 18A of the followers 16, 18. Inthese embodiments, the inner surfaces 40A, 42A of the housing half 24and/or the inner surfaces 44A, 46A of the housing half 24 are at least2, 3, or 5 points softer than the outer surfaces 16A, 18A of thefollowers 16, 18 as measured on the Rockwell Hardness scale. Forexample, in some embodiments where the housing 20 and the followers 16,18 are made from steel, the hardness of the inner surfaces 44A, 46A is40 HRC and the outer surfaces 16A, 18A have a hardness of at least 42,43, or 45 HRC.

In other embodiments, minimizing wear on of the outer spherical surface52 can be an objective of the joint 10. For example, in some embodimentsthe housing halves 24, 26 can be manufactured more cheaply and/or areeasier to service and replace than pivot member 22. To this end, theouter spherical surface 52 can have a hardness greater than a hardnessof the inner spherical surface 28 and/or inner spherical surface 30 ofthe first and second housing halves 24, 26, respectively. In theseembodiments, the outer spherical surface 52 can have a hardness at least2, 3, or 5 points greater than the hardness of the inner sphericalsurface 28 and/or inner spherical surface 30 of the first and secondhousing halves 24, 26, respect as measured on the Rockwell Hardnessscale. For example, in some embodiments where the housing 20 and thefollowers 16, 18 are made from steel, the hardness of the outerspherical surface 52 can be 48 HRC and the inner spherical surface 28and/or inner spherical surface 30 can have a hardness of less than 46,45, or 40 HRC.

In other embodiments, minimizing wear on the inner spherical surface 28and/or inner spherical surface 30 can be an objective of the joint 10.For example, in some embodiments the housing halves 24, 26 can bemanufactured less cheaply and/or are more difficult to service andreplace than pivot member 22. To this end, the outer spherical surface52 can have a hardness less than a hardness of the inner sphericalsurface 28 and/or inner spherical surfaces 28, 30 of the first andsecond housing halves 24, 26, respectively. In these embodiments, theouter spherical surface 52 can have a hardness at least 2, 3, or 5points lower than the hardness of the inner spherical surface 28 and/orinner spherical surface 30 of the first and second housing halves 24,26, respect as measured on the Rockwell Hardness scale. For example, insome embodiments where the housing 20 and the followers 16, 18 are madefrom steel, the hardness of the outer spherical surface 52 can be 40 HRCand the inner spherical surface 28 and or 30 can have a hardness of morethan 42, 43, or 45 HRC.

FIGS. 6-11, depict another aspect of the present disclosure wherein ajoint 10 a is applied to a socket wrench 78. On one end of the joint 10a, a first-half 80 of the housing 82 can be sized and configured tomount to a socket drive mechanism 84. The socket drive mechanism 84 canhave a spring detent that holds the first-half 80 of the joint 10 a ontothe socket wrench 78.

The socket wrench 78 drives the housing 82 and a socket connector 86,which can be removably secured to the socket 88. The joint 10 a allows amechanic or user to rotate a screw, nut or bolt in a hard-to-reach areaeven if it is not accessible and does not have a line of sight to thesocket wrench 78.

The joint 10 a operates in a similar manner as that described inrelation to the joint 10 as shown in FIGS. 1-5. Along these lines, thejoint 10 a can have a two-part housing 82 that includes the first-half80 and a second-half 85. The two halves 80, 85 collectively form atleast a portion of a spherical cavity by way of inner surfaces 90, 92.The inner surfaces 90, 92 are joined at the inside surfaces 94, 96 ofthe first and second halves 80, 85. This junction defines the equator ofthe spherical cavity defined by the inner surfaces 90, 92. Moreover, thejoint 10 a has an inner spherical member 98 which is trapped between thefirst and second halves 80, 85 within the spherical cavity defined bythe inner surfaces 90, 92.

The joint 10 a additionally has followers 16, 18 that are pinned to theinner member 98 by way of pin 95. The pin 95 extends through the innerspherical member 98 and protrudes out of the outer surfaces from theinner member 98. The followers 16, 18 each include a through hole orrecess 97, 99 which receive pin 95 and allows the followers 16, 18 topivot with respect to the inner member 98. The first and second halves80, 85 of the housing 82 can be held together by way of screws 87.

The first and second halves 80, 85 also have notches 70, 71, 72 and 73which receive the followers 16, 18. The outer surfaces 16A, 16B of thefollowers 16, 18 defines a configuration which is generallycomplimentary in shape to the interior surfaces of the notches 70, 71,72, 73. The outer surfaces 16A, 16B of the followers 16, 18 slide withinthe notches 70, 71, 72, and 73. The interior surfaces of the followers16, 18 can at least partially define a spherical configuration whichmates with the spherical outer surface of the inner member 98.

The joint 10 a can have a set screw 53 to temporarily hold the angle 81between the first shaft (i.e., socket drive mechanism 84) and the secondshaft (i.e., socket connector 86). The distal tip of the set screw 53can be Teflon coated. The set screw 53 can be threaded into tapped hole55. The tapped hole 55 can be aligned so that the set screw bears downon the exterior surface of the inner member 98. However, it is alsocontemplated that the tapped hole 55 can be formed in the housing sothat the set screw bears down on the outer surfaces 16A, 16B of eitherone of the followers 16, 18. The user can set the angle between thefirst and second shafts by holding the socket connector 86 in a relativeposition to the socket drive mechanism 84 and tightening set screw 53that bears down on the exterior surface of the inner member 98. The setscrew 53 can have a Teflon tip to prevent any marring on the exteriorsurface of the inner member 98.

The joint 10 a can be rotated to turn a bolt 79. The socket wrench 78 isconnected to the first half 80 of the housing 82 of the joint 10(a). Thesocket 88 is attached to the socket connector 86 (see FIG. 7). The anglebetween the bolt 79 and the socket drive mechanism 84 can be positionedand set in place by tightening set screw 53 which bears down on theinner member 98. In this manner, the socket wrench 78, joint 10 a,socket 88 and the bolt 79 can be set at an angle 81. The user canmaneuver the bolt 79 into position by sole use of the handle of thesocket wrench 78.

Manufacturing Methods of Universal Joint

An aspect of some embodiments described herein includes the realizationthat the effective service life of a joint can be extended and/or thedynamic loading capacity of the joint can be increased by theapplication of heat treatments to the sliding components of any of thejoints described herein (including joints 10 and 10 a and other jointsdescribed below). Although described herein in terms of the slidingcomponents of the joint 10 (including the housing 20, the followers 16,18, and the pivot member 22), corresponding components in other jointembodiments described herein can be treated following the same methods.Through application of manufacturing steps described in relation toFIGS. 12-16, the inner surfaces 40A-46A of the notches 40-46, the innerspherical surfaces 28, 30, the outer surfaces 16A, 18A of the followers16, 18 and/or the outer spherical surface 52 of the pivot member 22 canbe made more wear resistant and/or the useful life and torque capacitiesof the joint 10 can be enhanced.

FIG. 12 illustrates manufacturing steps according to process 100 forheat treating the sliding components of the joint 10 when made fromcarbon steel. Step 102 comprises manufacturing the components of thejoint 10 as described above using conventional manufacturing andmachining methods. In some embodiments of the present disclosure, thesliding components of the above described joint are manufactured fromcarbon steel using conventional and well-known machining and fabricationmethods. These methods can include, but are not limited to anycombination of machining from steel using milling and lathe techniques,broaching, casting, forging, powder metallurgy, electrical dischargemachining (EDM), and other conventional techniques. Each of the slidingcomponents can be manufactured from a carbon steel; the carbon steel foreach sliding component can be the same or a different carbon steel fromany of the other sliding components. Characteristics of appropriatecarbon steels for the heat-treating process are discussed below, but arein no way limited to the steel types listed herein. Appropriate carbonsteels include SAE 4000 steels such as 4140, 4340, and 300M.

Steps 104 and 106 comprise a heat treatment and a subsequent quench ofthe sliding component to form martensite. In some embodiments of themethod, Step 102 can be performed after steps 104 and 106. Heat treatingthe sliding components can cause slight deformations of the slidingcomponent's geometry, including the sliding or engaged surfaces. Inembodiments of the joint having tight tolerances, these slightdeformations can interfere with the assembly and operation of the joint.Thus, performing Steps 104 and 106 before the machining of Step 102 canbe advantageous by eliminating these deformations. In such embodiments,the steps 108 and 110 (described below involving cryogenic hardeningmethods) can be performed after Step 102. In some embodiments, thetempering of Step 112 can be performed either before or after Step 102,depending on the desired hardness of the sliding components during themachining of Step 102.

Step 104 comprises raising the temperature of the components to acritical temperature of the steel, the critical temperature being abovea eutectoid temperature of the steel and at which point the solidsolution iron-carbon system converts into austenite (also known as gamma(γ) phase iron) under equilibrium conditions.

FIG. 14 illustrates a binary phase diagram showing equilibriumallotropes of an unalloyed iron-cementite system. The unalloyediron-cementite phase system illustrated in FIG. 14 is used herein toillustrate and explain essential concepts of the present method. Point Ain FIG. 14 illustrates the eutectoid point at 727 degrees Celsius of theiron-cementite. Below the austenitic lines D and E, but above thecritical temperature a fraction of the microstructure of the steel willbe converted into austenite (with the other materials being ferrite andcementite). The austenitic lines D and E define the bottom extreme ofthe fully austenitic zone B.

Suitable steels for the heat-treating steps described in Steps 104 and106 have similar phase diagrams to FIG. 14. Depending on the presence ofadditional alloying elements in the steel (such as Cr, V, Bo, and Ni),the critical temperature (and other physical properties of the steel)can be higher or lower than that of unalloyed iron-carbon as shown inFIG. 14 and can occur at a different carbon content. Suitable steels forthe method described in FIG. 14 include other hardenable carbon steels(capable of the austenite to martensite conversion described as a partof the process 100).

In some embodiments of the present method of manufacture, the entirevolume of the steel is converted into austenite, such as would occurwhen the steel is held above the critical temperature long enough fornear-equilibrium conditions to be met. FIG. 14 illustrates the fullyaustenitic phase at Zone B. Point C represents the maximum solubility ofcarbon and iron within the austenite phase (2.03 wt. %). Thus, for acomplete or substantially complete conversion of the steel intoaustenite, the steel cannot include more than the maximum carbon content(this maximum solubility level can be varied based on the presence ofother alloying metals in the carbon steel).

Step 104 can include elevating the temperature of the steel of thesliding component and holding it at a temperature above the criticaltemperature for an austenitizing time to substantially complete atransformation of the steel into austenite from cementite (Fe3C) and/orferrite alpha-phase iron (a). In some embodiments of the method, thecomponent is held above the critical temperature for 95% of the steel tobe converted into austenite. Depending on the mass and geometry of thecomponent, an austenite conversion time may be higher or lower.Typically, the austenitizing time is 1 hour. The following chart for thesliding component parts of joint 10 illustrates exemplary criticaltemperatures at which 95% of the steel is converted into austenitewithin 1 hour.

Temperature Sliding Component (Celsius) Material Housing Half 24 815 SAE4340 Housing Half 26 815 SAE 4340 Followers 16, 18 871 300M (together)Pivot Member 22 871 300M

Austenite has a face centered cubic (FCC) crystalline structure andincludes carbon atoms within interstitial vacancies created in the FCCstructure. Cooling austenite below the critical temperature allows theaustenite to convert into ferrite and/or cementite, a body centeredcubic (BCC) crystalline structure, but if the cooling is slow enough forthe carbon in austenite to diffuse out of the austenite and combine withiron atoms and other carbon atoms to form ferrite or cementite. In suchcases, the ferrite and cementite form in alternating lamellar layersknown as bainite or pearlite.

Step 106, on the other hand, comprises cooling the formed austenitefaster than the carbon atoms can diffuse out of the austenite intoeither ferrite or cementite. As a result of fast quenching, theaustenite converts into martensite, a non-equilibrium phase iron alloythat traps the excess carbon atoms within microvoids in the martensiticcrystal structure before they can diffuse out of the austenite and formeither cementite or ferrite.

FIG. 15 illustrates an exemplary CCT (Continuous Cooling Transformation)diagram for a carbon steel. Such CCT diagrams are used to select quenchrates for specific steels held at austenizing temperatures based on thedesired microstructure of the steel. As illustrated in FIG. 15, coolingsteel in an austenitic phase at a rate slower than approximately 50°(C)/sec results in a significant formation of a bainite microstructure.Such results can be typically obtained through oil quenching, airquenching, or furnace cooling. Cooling the steel in an austenite phaseat a rate faster than approximately 50° (C)/sec substantially avoids theformation of a bainite microstructure in favor of a martensiticmicrostructure. Such results can be typically obtained through waterquenching or similar fast quench materials. Each carbon steel used inthe manufacture of the joint 10 has its own unique CCT diagram fromwhich appropriate cooling rates for quenching the steel in an austeniticphase to form martensite can be derived.

With continued reference to FIG. 15, as a part of step 106, the slidingcomponent is cooled quickly below a martensitic start temperature (MS)at which point austenite begins to convert into martensite and belowwhich additional austenite is converted into martensite until amartensitic finish temperature (MF) is reached. FIG. 16 illustrates amartensite start (MS) temperature and martensite final (MF) temperaturechart for an unalloyed iron-cementite system, up to 2.0 wt. % carbon.

Ideally, the MS temperature (and subsequently the MF temperature) isreached as quickly as possible to limit the amount of pearlite orbainite formed along the grain boundaries of the austenite asillustrated in FIG. 16. The conversion of austenite to martensite isseldom perfect and can be substantially lower than a completetransformation. In some embodiments of Step 106, at least 95% of themicrostructure of the steel is converted into martensite (as usedherein, the % symbol alone refers to % volume).

The MS and MF temperatures also vary greatly, depending on the alloyproperties (including carbon content) of the steel type. For example,for some carbon contents of steel, as illustrated in FIG. 16, the MFtemperature is below room temperatures (approximately 20° (C)). Thus,the complete transformation of austenite into martensite cannot becomplete by cooling to room temperature. Moreover, even when the MFtemperature is reached by the time the steel is quenched to roomtemperature, the steel can still include retained austenite because ofmechanical stresses within the martensitic microstructure. The resultingmartensitic structure of the steel can include as much as 17% retainedaustenite to as little as 3% or lower. Completion of the martensiticconversion is addressed further below in relation to Step 110 directedto cryogenic temperature treatment.

Step 108 comprises tempering the selected component below the criticaltemperature. By tempering below the critical temperature, themartensitic microstructure created within the steel by the above stepscannot be converted back into austenite. However, internal stresses fromthe creation of martensite can be relieved through tempering. Inaddition, precipitated eta-carbides can be grown within defects in themartensitic structure, and any remaining austenite can be decomposedinto cementite through tempering. This tempering decreases thebrittleness of the selected component and increases its ductility andtoughness while maintaining the same martensitic structure. Depending onthe desired hardness of the sliding components, the temper temperatureand temper time can be selected to achieve maintain that desiredhardness. For example, after quenching in water, 4340 steel can have ahardness of a maximum of approximately 60 HRC. After tempering at 550°C.) for one hour, the hardness can be reduced to approximately 40 HRC.

Generally selecting greater temper temperatures and greater temper timescreates components having greater toughness and less hardness andtherefore less wear resistance. In some embodiments of the presentdisclosure where the follower or followers 16, 18 are tempered at highertemperatures and/or longer than the housing halves 24, 26. Thus, thewear resistance of the more complex housing half components can becontrolled relative to the wear resistance of the follower or followers16, 18 that are more easily manufactured. In some embodiments, thehardness of either of the tempered housing halves 24, 26 is greater thanthe hardness of the outer surfaces 16A, 18A of the followers, 16, 18. Insome embodiments, the hardness of either of the tempered housing halves24, 26 is at least 2, 3, or 5 points greater on the Rockwell Hardnessscale than the hardness of the outer surfaces 16A, 18A of the followers,16, 18.

In some embodiments of the present disclosure the housing halves 24, 26are tempered at higher temperatures and/or longer than the outerspherical surface 52 of the pivot member 22. Thus, the wear resistanceof the pivot member 22 can be controlled relative to the wear resistanceof the housing halves 24, 26 that wear less quickly. In someembodiments, the hardness of either of the tempered outer sphericalsurface 52 is greater than the hardness of the inner spherical surfaces28, 30 of the housing halves 24, 26. In some embodiments, the hardnessof outer spherical surface 52 is at least 2, 3 or 5 points greater onthe Rockwell Hardness scale than the hardness of the inner sphericalsurfaces 28, 30.

In some embodiments, the heat-treating method can end after Step 108.For example, steels having a MF temperature above room temperature willhave ostensibly completed the martensitic transformation by cooling toroom temperature. As such, further treatment can be unnecessary once thedesired hardness of the sliding components is reached. However, in someembodiments, further treatment using cryogenic methods can impartadditional advantages to the resulting sliding components as describedbelow (including to those steels with a MF temperature above roomtemperature). As such, in some embodiments Step 108 can be performedbefore or after Steps 110 and 112.

The heat treatment steps of the process 100 can be used to create thedifferential hardnesses of the sliding surfaces as described above inthe context of the joint 10. Equally the steps of the process 100 can beused to create the differential hardnesses of the sliding surfaces forthe joints 10 a and other joints described herein.

Another aspect of the present disclosure is the realization that theeffective service life of a joint can be extended and/or the dynamicloading capacity of the joint can be increased by the application ofcryogenic treatments to the sliding components of the joint 10 (housinghalves 24, 26, follower or followers 16, 18, and pivot member 22).Through the application of the manufacturing steps described below andin relation to FIG. 12, the inner surfaces 40A-46A, the inner sphericalsurfaces 28, 30, and/or the outer spherical surface 52 of the pivotmember 22 can be made more wear resistant by reducing the amount ofretained austenite and by achieving a more uniform martensitic grainstructure. FIG. 12 further illustrates manufacturing steps to apply acryogenic treatment to the sliding components of the joint 10. Thesesteps can be applied variously to any or all the sliding-wear componentsof the rotational connecter 10, namely the first and second housinghalves 24, 26 and the pivot member 22. Thus, in some embodiments, thesliding components as discussed below can include the first and/orsecond housing halves 24, 26 and the pivot member 22. The slidingcomponents for the cryogenic treatment are referenced herein as thecomponents of the joint.

Step 110 comprises further cooling the components to below roomtemperature to a cryogenic temperature. Effective cryogenic temperaturescan be as low as −115° C. or −184° C. Cooling the components within thecryogenic temperature range continues the conversion of retainedaustenite to martensite to form a more complete martensitic matrix.Retained austenite acts as a weak spot within the matrix of themartensite and reduces the overall resistance of the material tocompressive loading and renders it more susceptible to cracking.Minimizing or removing the retained austenite improves wear propertieson surfaces by creating a more uniform martensitic structure anddispersing other alloy elements that can be present within the matrix byreducing the solubility of these elements within the matrix. The neteffect of these changes is to create a more stable, and therefore moredurable, material.

Sub-room temperatures are not necessary for completing the quench of thesteel to below the MF temperature for some steels, as indicated in FIG.16. Above approximately 0.5 wt. % Carbon, room temperature is below theMF temperature of the steel, indicating completion of the martensitictransformation. Thus, cryogenic treatment is required to reach the MFtemperature for these steels. However, cryogenic treatment has benefitseven for these steels that do not require cryogenic temperatures tocomplete the martensitic transformation. A steel can contain retainedaustenite that is not converted into martensite, despite having reachedthe MF temperature. Cryogenic treatment can be used to fully convert orminimize this retained austenite, the benefits of which have just beendiscussed above. Furthermore, cryogenic treatment precipitates microfineeta-carbides within microvoids of the martensitic structure, closing thegrain structure and adding compressive strength and density to the steeland improving its wear resistance.

Step 112 comprises maintaining the selected component below thecryogenic temperature for an effective bath time. Because of the slowtransformation rate of the retained austenite to martensite at cryogenictemperatures, bath times can be for between 12 and 24 hours or more,with a minimum of approximately 8 hours. Moreover, cooling components tocryogenic temperature requires controlled temperature drops to avoidrapid changes in the component's temperature that risk creating cracksin the component. An exemplary temperature profile for cryogenichardening gradually drops the temperature of the component from roomtemperature to below −184° C. for the first 6 hours of the process;holds the temperature for approximately 12 hours and then graduallyraised the temperature back to room temperature over the next six hours.In another example, the temperature of the component is droppedgradually below −115 hours and held between 8 and 24 hours beforegradually being returned to room temperature.

In some embodiments of the cryogenic treating process, austeniticstainless steel is used as outlined in FIG. 13 showing an austeniticstainless steel process 200 for hardening austenitic stainless steels.Austenitic stainless steels contain high amounts of nickel and chromium.For example, SAE 304 contains 17.5% chromium and 8-11% nickel, amongother alloying elements. Austenitic stainless steels exhibit austeniteas their primary phase at room temperature and thus are not hardenableby heat treatments. Nonetheless, cryogenic treatment of components madefrom austenitic steel exhibit improved wear and load capacities comparedto untreated austenitic steels. The cryogenic treating process, forexample precipitate carbides within the austenitic microstructure andthereby improves toughness without losing hardness.

Step 202 comprises manufacturing the components of the joint asdescribed herein using conventional manufacturing and machining methods(e.g., as described in relation to Step 102) and using an austeniticstainless steel for at least one of the sliding components. Appropriateaustenitic steels include, but are not limited to, Nitronic 50, SAE 304SS, and SAE 316 SS.

Step 204 comprises further cooling the components to below roomtemperature to a cryogenic temperature. Effective cryogenic temperaturescan be as low as −115° C. or −184° C., as described above.

Step 206 comprises maintaining the selected component below thecryogenic temperature for an effective bath time. Bath times can be forbetween approximately 12 and 24 hours or more. Moreover, coolingcomponents to cryogenic temperature requires controlled temperaturedrops to avoid rapid changes in the component's temperature that riskcreating cracks in the component. An exemplary temperature profile forcryogenic hardening gradually drops the temperature of the componentfrom room temperature to below −184° C. for the first 6 hours of theprocess; holds the temperature for approximately 12 hours and thengradually raised the temperature back to room temperature over the nextsix hours. In another example, the temperature of the component isdropped gradually below −115 hours and held between 8 and 24 hoursbefore gradually being returned to room temperature.

The above methods and steps comprising cryogenic hardening impartdistinct and beneficial properties on the sliding components of thejoint 10. For example, cryogenic hardening has the effect of increasingwear resistance, increases hardness and toughness, and/or reducing thecoefficient of friction of the surfaces of the sliding components. Forexample, the cryogenic hardening steps of the processes 100 and 200 canbe used to create the differential hardnesses of the sliding surfaces asdescribed above in the context of the joint 10. Equally the austeniticstainless steel process 200 can be used to create the differentialhardnesses of the sliding surfaces for the joints 10 a and other jointsdescribed herein.

Vapor deposition coatings can include physical vapor deposition (PVD),chemical vapor deposition (CVD) and similar processes such aslow-pressure chemical vapor deposition and plasma-assisted chemicalvapor deposition. Furthermore, PVD describes many different coatingprocesses that take place within a vacuum or near-vacuum and generallyinvolve the bombardment of a substrate with positively charged ions.Various reactive gases can also be introduced into the vacuum chamber tocreate chemical compound coatings. As such, the coating depth,composition, and bonding can be highly tailored for specificapplications. PVD industrial coatings include titanium nitride,zirconium nitride, chromium nitride, aluminum nitride, all of which areappropriate for steels.

CVD is also conducted within a CVD reactor with specific atmospheretypes and at elevated temperatures (approximately 1000° C.). In CVD, thesurface of a substrate is heated and a thin-film coating is formed onthe surface as the result of reactions between the surface and variousgaseous phases within the CVD reactor. CVD industrial coatings for wearresistance include titanium carbide, titanium nitride, aluminum oxide,aluminum titanium nitride, chromium carbide, chromium nitride,molybdenum disulfide, niobium carbide, titanium aluminum nitride,titanium carbon nitride, and zirconium nitride coating.

According to some aspects of the method of manufacture of a jointdescribed herein, vapor deposition coatings, including PVD and CVD, canbe applied to the any of the outer surfaces 16A, 16B of the followers16, 18 and/or any combination of the inner surfaces 40A-46A of thenotches 40-46 of the housing halves 24, 26. The wear between the slidingcomponents of the joint can thus be reduced, improving service life andreliability of the joint. In addition, the outer surface 52 of the pivotmember 22 can be coated and/or the inner spherical surfaces 28, 30 ofthe housing halves 24, 26. Thus, the wear resistance of the more complexor more expensive to produce sliding components can be controlledrelative to the wear resistance of the less expensive or cheaper toproduce sliding components.

In some embodiments of the method of manufacture of a joint describedherein, the coating hardness of the sliding components can be 64 HRC. Inother embodiments, the coating hardness of the sliding components can befound within the ranges in the table below.

Joint Component Coating Hardness Range (HRC) inner (cylindricalsurfaces) 40A-46A 60-68 inner (spherical surfaces) 28, 30 60-68 outer(cylindrical surfaces) 16A, 18A 60-68 outer (spherical) surface 52 60-68

In addition to the heat treating, cryogenic, and vapor depositionmethods described above (and combinations of these methods), someembodiments of the method of manufacture can further comprise themethods of case hardening and/or shot-peening of the sliding components.Each of these methods enhances the wear resistance and hardness of thesliding surfaces of the sliding components.

Case-hardening comprises hardening the outer surface of the slidingcomponents and allowing the metal underneath to remain softer and moreductile. Case hardening can also infuse additional carbon into the outersurface layer, enabling it to reach higher hardness than other possiblefor low-carbon content steels. Case hardening can be performed throughvarious methods such as but not limited to using flame or inductionhardening, carburizing (for low-carbon content steels), and nitriding.Because of the minimal distortions caused by case-hardening, the slidingcomponents of the joint can be case-hardened after being machined.Referring to FIG. 12 and the process of heat treating carbon steeloutlined above, case-hardening can be performed after the machining Step102 and the part has been shaped into its final form. For example, anyor all of the components of the joint 10 or 10 a can be nitrided toimprove the wear properties thereof (e.g., surfaces of the slidingcomponents). In one exemplary process of nitriding, the components areheated to between 482-621° C. (900-1,150° F.) (for steel parts) andexposed to a nitrogen rich gas in the form of ammonia (NH3). Whenammonia contacts the heated component it dissociates into nitrogen andhydrogen and diffuses into the surface in the form of a nitride layer.The case hardening can occur after the components are quenched, temperedand/or machined because it causes little to no distortion.

Shot peening produces a compressive residual stress layer in a surfaceof a component and increases the hardness of the surface. The methodincludes impacting the surface with shot (metallic, glass, or ceramicparticles) with sufficient force to create minor plastic deformation andis considered a cold working process. Methods of shot peening include,but are not limited to propelling shot using centrifugal blast wheelsand air jets. Because of the minimal distortions caused by shot peening,the sliding components of the joint can be shot peened after beingmachined. Referring to FIG. 12 and the process of heat treating carbonsteel outlined above, shot-peening can be performed after the machiningStep 102 and the part has been shaped into its final form.

Third Embodiments of a Universal Joint

FIGS. 17-25 illustrate another embodiment of a joint 300. Joint 300 caninclude a housing 330, a drive puck 370, a drive ball 350, a pin 380 anda cap ring 390, in addition to various fasteners, as described below.Like the joints 10 and 10 a, the joint 300 can couple together a firstshaft and a second shaft (not shown) such that rotation of the firstshaft about its longitudinal axis matches rotation of the second shaftabout its longitudinal axis. For example, rotation of the first shaftcan match rotation of the second shaft in a 1:1 ratio.

The first shaft can be coupled with the housing 330. The second shaftcan be coupled with the drive ball 350. The drive ball 350 can becoupled with the housing 330 by the drive puck 370 and the pin 380. Thedrive puck 370 can couple with the housing 330 and rotate with respectto the housing 330 in a first plane. The drive ball 350 can be coupledwith the drive puck 370 and thereby rotate with respect to the housing330 in the first plane. The drive ball 350 can be coupled with the drivepuck 370 by the pin 380 and rotatable about the pin 380 with respect tothe drive puck 370 in a second plane. In this manner, the drive ball 350can be rotatable with respect to the housing 330 in both the first andsecond planes. In some embodiments, the first and second planes aresubstantially orthogonal to each other.

A longitudinal axis of the drive ball 350 can be set at an angle 317with respect to a longitudinal axis of the housing 330, as illustratedin FIG. 18. Angle 317 can be created by rotation of the joint 300 abouteither the drive puck 370 and/or the pin 380. In this manner, the firstshaft can be angled with respect to the second shaft as the first andsecond shaft rotate together. In some embodiments, angle 317 can beadjusted between approximately 0° and a maximum of approximately 45° to50°. In some embodiments of the joint 300 (e.g., where the first andsecond shaft are braced), that angle 317 is maintained as rotation fromthe first shaft is transferred across the joint 300 into the secondshaft. Angle 317 can be maintained as the joint 300 rotates bycorresponding rotations of the drive ball 350 about the pin 380 and byrotation of the drive puck 370 with respect the housing 330.

As shown in detail in FIGS. 20-21, the housing 330 can include a housingbody 333 with a first end 331 and a second end 332. The housing body 333can be tubular in nature and an inner wall 337 of the housing body 333can define an inner space 334. In some embodiments, the inner space 334extends between the first end 331 and the second end 332 (e.g., throughthe housing body 333). The second end 332 can include an opening to theinner space 334. The opening can be circular, square, rectangular,hexagonal, or any other suitable shape. The second end 332 can beconfigured to be coupled with the first shaft of the joint 300. Forexample, the inner wall 337 of the housing at the second end 332 caninclude splines that can securely couple with an end of the first shaft.In some embodiments, second end 332 can include tapered hole 338 throughwhich a set screw can be inserted to secure the end of the input shaftwithin the second end 332.

The first end 331 of the housing 330 can include a channel 335. Thechannel 335 can be formed on the inner surface 337 of the housing body333. The channel 335 can comprise a cylindrical bottom surface. Thecylindrical bottom surface can be oriented around a single axis ofrotation. The single axis of rotation can be located at the first end331 of the housing 330. The cylindrical bottom surface can be dividedinto a first channel surface 335 a and a second channel surface 335 b.The first and second channel surfaces 335 a, 335 b can be separated bythe inner space 334. First and second sidewall surfaces 335 c, 335 d canextend from the cylindrical bottom surface to further define the channel335. The sidewall surfaces 335 c, 335 d can be set at approximately aright angle with the cylindrical bottom surface. The first and secondchannel surfaces 335 a, 335 b can each interface with the first end 331of the housing 330 at an equatorial line of the cylindrical bottomsurface (dividing the cylindrical bottom surface in half).

The first end 331 of the housing 330 can further include a concavespherical surface 336. The spherical surface can be disposed within thehousing wall 333 adjacent to the opening of the first end 331. Thespherical surface 336 can include a partial surface segment or segmentsof a sphere. The sphere can be centered at the same point as the singleaxis of rotation defining the channel 335. The spherical surface 336 caninclude first and second spherical surfaces 336 a, 336 b. The first andsecond spherical surfaces 336 a, 336 b can be divided by the inner space334. The first and second spherical surfaces 336 a, 336 b can eachinterface with the first end 331 of the housing 330 at an equatorialline of the spherical surface 336.

The first end 331 of the housing 330 can include an interface surface331 a. The cap ring 390 can couple with the housing 330 at the interfacesurface 331 a. The first end 331 can include one or more tapped holes339 a. The cap ring 390 can include one or more corresponding throughholes 398 (shown in detail in FIGS. 22A-C) through which one or morescrews can be inserted to couple the cap ring 390 with the first end 331of the housing 330. In some embodiments the first end 331 of the housing330 can include four tapped holes 339 a that are set in a squareconfiguration. The square configuration allows for a stable connectionwith four sides of the cap ring 390.

For alignment purposes, the interface surface 331 a and the cap ring 390can include one or more posts or recesses 339 b. The one or more postsor recesses 339 b on the interface surface 331 a can correspond to oneor more corresponding posts or recesses 393 a, 393 b on the cap ring390. The posts or recesses 393 a, 393 b can function to align the firstend 331 of the housing 330 with the cap ring 390 for assembly of the capring 390 with the first end 331 of the housing 330.

The cap ring 390 can include first and second faces 391 a, 391 b. Thesecond face 391 b can be planar in nature. The cap ring 390 can includethe one or more through holes 398 for receiving screws to attach the capring 390 with the housing 330. In some embodiments the screw holes 398include counter sunk portions such that screws can be flush with thefirst face 391 a of the cap ring 390.

The cap ring 390 can further include first and second channel segments397 a, 397 b. The channel segments 397 a, 397 b can be cylindrical inshape. In some embodiments the channel segments 397 a, 397 b aredisposed on opposite sides of the cap ring 390 from each other. Thechannel segments 397 a, 397 b can interface with the second face 391 bat an equatorial line.

The cap ring 390 can further include a concave spherical surface 394.The concave spherical surface 394 can interface with the second face 391b at an equatorial line of the concave spherical surface 394. There canbe one or more concave spherical portions 394 on the cap ring 390. Forexample the cap ring 390 can include first and second concave sphericalsurfaces 394 a, 394 b. In some embodiments these surfaces are disposedon opposite sides of the cap ring 390 divided by the channel segments397 a, 397 b.

The cap ring 390 can include a central opening 392. Central opening 392can be generally circular in nature. The channel segments 397 a, 397 bcan be disposed around the central opening 392 (e.g., on opposite sidesof the central opening 392), some embodiments of the cap ring 390 caninclude a chamfer 395 between the first surface 391 a and the centralopening 392.

The drive puck 370, shown in detail in FIGS. 23A-B, can include an outersurface 372. The outer surface 372 can have a circular profile whenviewed from the top, as in FIG. 23B. The outer surface 372 can be acylindrical surface that is disposed about a central axis. The drivepuck 370 can further include first and second wings 375 a, 375 b. Thedrive puck 370 can further include an inner slot 373. The first andsecond wings 375 a, 375 b can be disposed on opposite sides of the innerslot 373. The inner slot 373 can include first and second sidewalls 374a, 374 b. The first and second sidewalls 374 a, 374 b can be disposedopposite each other within the inner slot 373.

In some embodiments one or both of the sidewalls 374 a, 374 b compriseplanar portions. The planar portions of the first and second sidewalls374 a, 374 b can be substantially parallel to each other. A shaft 377can extend through either one or both of the first and second wings 375a, 375 b. The shaft 377 can extend through the first and second wings375 a, 375 b or the planar portions of the first and second wings 375 a,375 b, in some embodiments. An upper face 376 a of the drive puck 370can be substantially planar. A lower face 376 b of the drive puck canalso be substantially planar and substantially parallel to the upperface 376 a. In some embodiments one or both of the first and secondsidewalls 374 a, 374 b are set at right angles with either one or bothof the upper and lower faces 376 a, 376 b.

The drive puck 370 can be slidingly engaged within channel 335 of thehousing 330. The outer surface 372 of the drive puck 370 can correspondto the first and second channel surfaces 335 a, 335 b. For example thedrive puck 370 can be disposed within the channel 335 and configured torotate by sliding against the first and second channel surfaces 335 a,335 b. Thereby the drive puck 370 can rotate substantially in a singleplane of motion within the channel 335.

The drive ball 350, shown in detail in FIGS. 24A-24C can include a ballend 351 and a socket end 353. The ball end 351 and the socket end 353can be coupled together by a neck portion 355. The ball end 351 caninclude a convex spherical surface 352. The ball end 351 can furtherinclude a shaft 357 disposed through the ball end 351. The ball end 351can include one or more planar regions 358 a, 358 b. For example theball end 351 can include first and second planar regions 358 a, 358 b.The planar regions 358 a, 358 b can be disposed on opposite sides of theball end 351 and can be substantially parallel to each other. In someembodiments, the shaft 357 extends through the planar regions 358 a, 358b.

The socket end 353 can include a socket 353 a. In some embodiments, thesocket 353 a can be configured to be coupled with the second shaft ofthe joint 300. For example the socket 353 a can include splines and atap screw for holding the output shaft within the socket 353 a. Thesocket 353 a can be circular, square, rectangular, hexagonal, or anyother suitable shape. In other embodiments the socket end 353 is a maleconnector or any other type of connector coupling the drive ball 350with the second shaft. The outer surface of the socket end 353 can becylindrical or any other suitable shape.

The pin 380 can be generally cylindrical in shape, as shown in detail inFIGS. 25A-C. The pin 380 can include first and second sides 381, 382with first and second ends 381 a, 382 a, respectively. The first andsecond sides 381, 382 can be separated, in some embodiments, by adepression 383.

The joint 300 can be assembled by inserting the ball end 351 within theinner slot 373 of the drive puck 370. The drive puck 370 can bepivotally coupled with the ball end 351 of the drive ball 350 with thepin 380. The pin 380 can be inserted through the shaft 377 and throughthe shaft 357. In some embodiments the ball end 351 can further includea set screw for securing the pin 380 within the shaft 357. The set screwis inserted through tapered hole 359 on the ball end 351 of the driveball 350. A tip of the set screw can be inserted into the depression 383of the pin 380 and thereby maintain it within the shaft 357.Alternatively, the set screw can contact an outer surface of the pin380.

The pin 380 can also be inserted into the shaft 377 of the drive puck370 to couple the drive puck 370 with the drive ball 350. The first andsecond sides 358 a and 358 b of the ball end 351 of the drive ball 350can align with and slidingly engaged with the inner sidewalls 374 a and374 b of the inner slot 373 of the drive puck 370. The sliding interfaceof the sidewalls and the first and second surfaces 358 a and 358 b canprovide stability to the rotation of the drive ball 350 with respect tothe drive puck 370. Further the inner slot 373 allows for a simpleinsertion of the ball end 351 within the inner slot 373 and disposingthe drive puck 370 around the ball end 351.

The inner sidewalls 374 a and 374 b of the inner slot 373 are thus animprovement from a manufacturing standpoint over the inner sphericalsurfaces 48, 50 of the followers 16, 18 of the joint 10 described abovethat mate with the outer spherical surface 52 of the pivot member 22.Machining the inner sidewalls 374 a and 374 b of the inner slot 373 (orthe first and second surfaces 358 a and 358 b of the drive ball 350)takes much less machining time than the inner surfaces 48, 50. The drivepuck 370 can be manufactured with less specialized equipment andprocesses than the followers 16, 18. For example, the inner sidewalls374 a and 374 b of the inner slot 373 can be manufactured using an endmill and removing material to form flat planes.

The concave spherical surface 336 can be slidingly engaged with theconvex spherical surface 352 of the drive ball 350. When assembledtogether the components of the joint 300 of the ball end 351 with theconvex spherical surface 352 can be slidingly engaged with the concavespherical surface 336 of the housing 330. Thereby compressional loadsfrom between the housing 330 and the drive ball 350 can be distributedat least partially through the concave spherical surface 336 and theconvex spherical surface 352.

The drive puck 370 can be inserted within the first end 331 of thehousing 330 and inserted within the channel 335. The outer surface 372can be slidingly engaged with the channel 335. The first and secondfaces 376 a, 376 b of the drive puck 370 can correspond and slidinglyengage with the sidewalls of the channel 335. This configuration canprovide stability for the drive puck 370 as it rotates in a single planewithin the channel 335. The rotation of the drive puck 370 within thechannel 335 can be substantially in the first plane. The rotation of thedrive ball 350 about the pin 380 within the drive puck 370 can besubstantially in the second plane. The first and second planes can beset orthogonal to each other.

The cap ring 390 fits over the drive ball 350 and against the first end331 of the housing 330. The first and second concave spherical surfaces394 a, 394 b of the cap ring 390 can slidingly engage with the convexspherical surface 352 of the ball end 351 of the drive ball 350. Thechannel segments 397 a, 397 b of the cap ring 390 can align with andslidingly engage with the outer surface 372 of the drive puck 370. Thesecond face 391 b can be disposed on the interface 331 a. This caninclude alignment of the post or receiving slot 373 of the housing 330with corresponding slots or receiving posts of the cap ring 390. The capring 390 can be coupled with the first end 331 of the housing 330 byinserting one or more screws through the screw holes 398 of the cap ring390 and into the corresponding tapped holes 339 a of the housing 330.

Once assembled the socket end 353 of the drive ball 350 can be pivotedin the first and second planes with respect to the housing 330. In someembodiments, rotation of the socket end 353 with respect to the housing330 is only limited by its interference with the chamfer 395 of the capring 390.

The manufacturing processes described above can also be applied inconjunction with the sliding components and surfaces of the joint 300.For example, the sliding components of the joint 300 (optionallyincluding the housing 330, the cap ring 390, the drive puck 370 and/orthe drive ball 350) can be heat treated (including processes 100 and200), vapor deposition coated, shot-peened, and/or case hardened.Through application of the manufacturing steps described above, theconvex spherical surface 352 and the concave spherical surface394/concave spherical surface 336 can be made more wear resistant and/orthe useful life and torque capacities of the joint 10 can be enhanced.Similarly, the channel 335 (optionally including the cylindrical bottomsurface and/or the first and second sidewall surfaces 335 c, 335 d) andthe channel segments 397 a, 397 b and the outer surface 372 can be mademore wear resistant and/or the useful life and torque capacities of thejoint 10 can be enhanced.

Fourth Embodiments of a Universal Joint

FIGS. 26-30 illustrate another embodiment of joint assembly 400. Joint400 can include a housing 430 with first and second ends 430 a, 430 b.Each of the first and second ends 430 a, 430 b can include a structuresimilar to the housing 330, drive puck 370, and drive ball 350 describedabove. The manufacturing processes described above (including processes100 and 200) can also be applied in conjunction with the slidingcomponents and surfaces of the joint 400.

The joint 400 can include first and second drive pucks, 470 a, 470 b,first and second drive balls 450 a, 450 b and first and second cap rings490 a, 490 b, in addition to various fasteners. Like the joints 10, 10a, and 300, joint 400 can couple together a first shaft and a secondshaft (not shown) such that rotation of the first shaft about itslongitudinal axis transfers to rotation of the second shaft about itslongitudinal axis. For example, rotation of the first shaft can matchrotation of the second shaft.

The first shaft can be coupled with the first drive ball 450 a. Thesecond shaft can be coupled with the second drive ball 450 b. The firstand second drive balls 450 a, 450 b can be coupled with first and secondends 430 a, 430 b of the housing 430 by the first and second drive pucks470 a, 470 b, respectively. The first drive puck 470 a can be coupledwith the first end 430 a and rotate with respect to the housing 430 in afirst plane 401. The first drive ball 450 a can be coupled with thefirst drive puck 470 a and thereby rotate with respect to the housing430 in the first plane 401. The first drive ball 450 a can be coupledwith the first drive puck 470 a by a first pin 480 a. The first driveball 450 a can be rotatable about the first pin 480 a with respect tothe first drive puck 470 a in a second plane 402. In this manner, thefirst drive ball 450 a can be rotatable with respect to the housing 430in both the first and second planes 401, 402. In some embodiments, thefirst and second planes 401, 402 are substantially orthogonal to eachother.

Similar to the first end 430 a of the housing 430, the second end 430 bcan couple with the second drive puck 470 b. The second drive puck 470 bcan be rotatable with respect to the housing 430 in a third plane 403.The second drive ball 450 b can be coupled with the second drive puck470 b and thereby rotate with respect to the housing 430 in the thirdplane 403. The second drive ball 450 b can be coupled with the seconddrive puck 470 b by a second pin 480 b. The second drive ball 450 b canbe rotatable about the second pin 480 b with respect to the second drivepuck 470 b in a fourth plane 404. In this manner, the second drive ball450 b can be rotatable with respect to the housing 430 in both the third403 and fourth planes 404. In some embodiments, the third 403 and fourth404 planes are substantially orthogonal to each other.

The first drive ball 450 a can be rotated to an angle 417 with respectto a longitudinal axis of the housing 430. Angle 417 can be maintainedduring rotation of the first shaft and joint 400 by rotation of thefirst drive ball 450 a and/or the first drive puck 470 a within thefirst and/or second planes 403, 404, respectively. The second drive ball450 b can be rotated to an angle 418 with respect to a longitudinal axisof the housing 430. Angle 418 can be maintained during rotation of thesecond shaft and joint 400 by rotation of the second drive ball 450 band/or the second drive puck 470 b within the third and/or fourth planes403, 404, respectively.

An angle 419 between the first and the second shaft can be adjustedbetween approximately 0° and a maximum of approximately 90° to 100°. Insome embodiments of the joint 400, it can be advantageous to createmaximum angle of approximately 90°. The angle 419 can be maintained asthe joint 400 rotates by corresponding rotations of the first and seconddrive pucks 470 a, 470 b within the first and third planes 401, 403 andby rotation of the first and second drive balls 450 a, 450 b within thesecond and fourth planes, 402, 404.

In a joint with a single rotational angle (e.g., joints 10, 10 a, 300),the rotational speed of the first shaft coupled with the joint does notalways match the rotational speed of the second shaft coupled with thejoint. Where the angle (e.g., angles 17, 117 described above) betweenthe first and second shaft is substantially zero, the rotational speedsof the first and second shafts match. However at non-zero angles, afluctuation (e.g., a sinusoidal variation in the rotational velocity)occurs across the joint. For example, first shaft can be angled at 450with the second shaft and the first shaft can have a constant rotationalspeed. Here, the rotational speed of the second shaft will fluctuatewith respect to the constant speed of the first shaft in a sinusoidalpattern. The greater the angle, the greater the peak of the fluctuatingrotational speed. This fluctuating rotational speed can typically befelt as a vibration of the joint during rotation.

To obtain a constant velocity between the first and second shafts, asecond angle can be added to the joint to phase out the fluctuationsentered at the first angle. In some embodiments of the joint 400, thefirst and third planes 401, 403 and the second and fourth planes 402,404 can be substantially orthogonal to each other. This phases thefluctuations entered by each of the angles 417, 418 to be substantiallyopposite each other. Furthermore, the angles 417 and 418 can bemaintained substantially equal to each other such that the magnitude ofthe fluctuations entered at both angles 417 and 418 will beapproximately equal and therefore cancel each out. In such aconfiguration, the joint 400 can be used as a constant velocity jointwith rotation of the first joint matching rotation of the second joint.In other embodiments, the first and third planes 401, 403 (and/or thesecond and fourth planes 402, 404) can be substantially parallel to eachother, but this will not typically result in a constant-velocity joint.In some embodiments, the alignment of the first and third planes can beopposite that conventionally known in a double Cardan joint. In a doubleCardan joint, the two universal joints are 90° out of phase at eitherend of an intermediate shaft and this configuration is a known constantvelocity joint. In contrast, some embodiments of the joint describedherein are not 90° out of phase at either end of the housing 430 and aresubstantially in-phase, as described above.

The first and second drive pucks 470 a, 470 b can have the samestructure as described above in relation to the drive puck 370. Thefirst and second drive balls 450 a, 450 b can have the same structure asdescribed above in relation to the drive ball 350. The first and seconddrive balls 450 a, 450 b can include convex spherical surfaces 452 a,452 b, first ends 451 a, 451 b, and second ends 453 a, 453 b,respectively. The joint 400 can include first and second pins 480 a, 480b. The first and second pins 480 a, 480 b can have the same structure asdescribed above in relation to pin 380.

As shown in FIGS. 27A-27B, housing 430 can include a housing body 433with the first and second ends 430 a, 430 b. The housing body 433 can betubular in nature and an inner wall 437 of the housing body 433 candefine an inner space 434. In some embodiments, the inner space 434extends through the housing body 433. In some embodiments, the secondend 430 b can be configured to be machined separately and coupled withthe first end 430 a (e.g., by welding or mechanical fasteners). In someembodiments, the housing body 433 is machined from an integral material.

Each of the first and second ends 430 a, 430 b can have substantiallythe same structural components as the first end 331 of the housing 330.The second end 430 b can include an opening to the inner space 434. Likethe opening of the housing 330, the opening of the second end 430 b canbe circular, square, rectangular, hexagonal, or any other suitableshape.

The first and second ends 430 a, 430 b of the housing 430 can includechannels 435 a, 435 b, respectively. The channels 435 a, 435 b can beformed in the inner surface 437 of the housing body 433. The channels435 a, 435 b can have the same structure as the channel 335 in joint300. The channels 435 a, 435 b can interface with the first and secondends 430 a, 430 b at an equatorial line of the channels 435 a, 435 b(dividing cylindrical bottom surfaces of the channels 435 a, 435 b inhalf), respectively. The first and second ends 430 a, 430 b can furtherinclude concave spherical surfaces 436 a, 436 b. The concave sphericalsurfaces 436 a, 436 b can have the same structure as the concavespherical surface 336 and with the first and second ends 430 a, 430 b atan equatorial line.

The first and second ends 430 a, 430 b of the housing 430 can interfacewith the first and second cap rings 490 a, 490 b. The cap rings 490 a,490 b can have the same structure as the cap ring 390 discussed above.The cap rings 490 a, 490 b can include one or more posts 496 a, 496 band corresponding recesses on the housing 430. The cap rings 490 a, 490b can include screw holes and screws 495 a, 495 b. The cap rings 490 a,490 b can each include channel segments, spherical surfaces, and centralopenings, similar to the cap ring 390 discussed above.

The joint 400 can be assembled by inserting the first end 451 a of thefirst drive ball 450 a within an inner slot of the first drive puck 470a. The first drive puck 470 a can be pivotally coupled with the firstend 451 a with the first pin 480 a. In some embodiments a set screwassembly 459 a can secure first pin 480 a in place. The first drive puck470 a can be inserted within the channel 435 a. An outer surface of thefirst drive puck 470 a can be slidingly engaged with the cylindricalbottom surfaces of the channel 435 a. The concave spherical surface 436a can be slidingly engaged with the convex spherical surface 452 a ofthe first drive ball 450 a. The first cap ring 490 a can be aligned withthe first end 430 a by one or more pins 496 a and coupled thereto byfasteners 495 a.

The first drive puck 470 a can rotate about a first central axis withinthe channel 435 a and within the first plane 401. The first drive ball450 a can rotate about the first pin 480 a and within the second plane402. The first central axis can intersect a longitudinal axis of thefirst pin 480 a.

The second drive ball 450 b can be assembled with an inner slot of thesecond drive puck and assembled therewith by the second pin 480 b. Thesecond drive puck 470 b can be assembled within the second channel 435b. The second drive puck 470 b can rotate about a second central axiswithin the second channel 435 b and within the third plane 403. Thesecond drive ball 450 b can rotate about the second pin 480 b and withinthe fourth plane 404. The second central axis can intersect alongitudinal axis of the second pin 480 b.

The second cap ring 490 b fits over the second drive ball 450 b andcouples with the second end 430 b of the housing 430 to secure thesecond drive ball 450 b within the housing 430. The second drive puck470 b can slidingly engage within the channel segments of the cap ring490 b and the channel 435 b. The convex spherical surface 452 b canslidingly engage the concave spherical surface 436 b and the concavespherical surface of the cap ring 490 b. The second cap ring 490 b canbe aligned with the second end 430 b by one or more pins 496 b andcoupled thereto by fasteners 495 b.

Once assembled the first and second drive balls 450 a, 450 b can bepivoted to the angles, 417, 418, respectively, with respect to thehousing 430. In some embodiments, rotation of the first and second driveballs 450 a, 450 b is only limited by its interference with the firstand second cap rings 490 a, 490 b, respectively.

Fifth Embodiments of a Universal Joint

FIGS. 31-43 illustrate another embodiment of a joint assembly 500.Similar in certain aspect to the function of the joints 10, 10 a and 300described above, the joint 500 offers certain improvements tomanufacturability, structure, and function, as described further below.

The joint 500 can include a housing 530, drive puck 570 and a drive ball550, as well as various fasteners. A first end 551 of the drive ball 550can be rotatably coupled with the drive puck 570. A second end 553 ofthe drive ball 550 can be configured to be coupled with a first shaft.For example, the second end 553 can comprise an aperture 553 a forreceiving an end of the first shaft. The drive puck 570 can be rotatablycoupled with the housing 530. Specifically the drive puck 570 can becoupled at a first end 531 of the housing 530. A second end 532 of thehousing 530 can configured to be coupled with a second shaft. Forexample, in some embodiments the second end 532 of the housing 530includes a recess 532 a for receiving an end of the second shaft (e.g.,an output shaft).

In this manner, the first and second shafts can be coupled together suchthat rotation from the first shaft can be transferred to rotation of thesecond shaft through the joint 500. In addition, an angle 517 can be hadbetween the first and second shafts and maintained during rotation ofthe first and second shafts and joint 500. FIG. 32A illustrates thedrive ball 550 rotated to angle 517 with respect to the housing 530. Theangle 517 can be adjusted between 0° and approximately 45° to 50°. Thedrive ball 550 can be rotatable within a first plane 501 with respect tothe housing 530. The drive puck 570 can be rotatable within a secondplane 502 with respect to the housing 530. The first and second plane501, 502 can be substantially orthogonal. This configuration can allowfor rotation of the joint 500 while maintaining the angle 517.

The housing 530, as illustrated in FIGS. 33A-35D can include first andsecond housing sections 530 a, 530 b. The first housing section 530 acan include an outer casing 533. The outer casing 533 can include aninner surface 537. The inner surface 537 can be disposed around and/ordefining a central cavity 534 of the outer casing 533. In someembodiments, the outer casing 533 can be substantially cylindrical onits exterior surface. In other embodiments, the outer casing 533 canhave any desirable shape or outer contour. In some embodiments, thecentral cavity 534 is substantially cylindrical in nature. The innersurface 537 can also comprise a cylindrical surface. In otherembodiments, the shape of the inner surface 537 and/or the centralcavity 534 does not contact any of the movable components of the joint500 as described further below.

The first housing section 530 a can include first and second grooves 535a, 535 b. The first and second grooves 535 a, 535 b can be disposed onopposite sides of the central cavity 534. The first and second grooves535 a, 535 b can be cylindrical in shape. The first and second grooves535 a, 535 b can be disposed within the inner surface 537 of the outercasing 533. The first groove 535 a can include a first concave slidingsurface 536 a. Similarly, the second groove 535 b can include a secondconcave sliding surface 536 b. The first and second concave slidingsurfaces 536 a, 536 b can extend from a first end 533 a to a second end533 b of the first housing section 530 a. The first end 533 a of thehousing section 530 a can include a flat surface that can be interfacedand joined with the second housing section 530 b of the housing 530 asdescribed below. The second end of 533 b of the first housing section530 a can be at an upper face 531 a of the first housing section 530 a.In some embodiments, the upper face 531 a can be rounded.

The first housing section 530 a can include first and second lips 538 a,538 b. In some embodiments, the first and second lips 538 a, 538 b areat the second end 533 b of the housing section 530 a. In someembodiments, the first and second grooves 535 a, 535 b are disposed onopposite sides of the central cavity 534. In some embodiments, the firstand second grooves 535 a, 535 b are facing each other and are mirrorimages of each other. The first and second lips 538 a, 538 b can extendinwardly towards a center such as a central longitudinal axis of thefirst housing section 530 a. The first lip 538 a can be aligned with thefirst groove 535 a. The second lip 538 b can be aligned with the secondgroove 535 b.

The first and second concave sliding surfaces 536 a, 536 b can extend atleast partially across the lips 538 a, 538 b, respectfully. In someembodiments, the first and second concave sliding surfaces 536 a, 536 bextend to the upper face 531 a of the first housing section 530 a fromthe first end 533 a of the first housing section 530 a. The first andsecond concave sliding surfaces 536 a, 536 b can include straightportions 536 c, 536 d, respectively. The straight portions 536 c, 536 dcan begin at the first end 533 a. The straight portions 536 c, 536 d canbe cylindrical in shape. The first and second concave sliding surfaces536 a, 536 b can include toroidal surface portions 536 e, 536 f,respectively. The toroidal surface portions 536 e, 536 f can couple withthe straight portions 536 c, 536 d and extend across the lips 538 a, 538b, respectively. The toroidal surface portions 536 e, 536 f can bedisposed radially inward of the straight portions 536 c, 536 d. Acenterline 536 g of the straight portion 536 c of the first concavesliding surface 536 a can be linear and parallel to a centerline 536 hof the straight portion 536 d of the second concave sliding surface 536b. A groove distance 535 c between the center lines 536 g and 536 h canbe constant throughout the straight portions 536 c, 536 d. A narrowerlip distance 538 c between the lips 538 a, 538 b can represent theshortest distance between the opposing surfaces of the toroidal surfaceportions 536 e, 536 f.

The toroidal surface portions 536 e, 536 f can correspond a convexsliding surface or toroidal outer surface 572 of the drive puck 570described below. At least one of the radii of curvature of the toroidalsurface portions 536 e, 536 f can be equal to approximately half thegroove distance 535 c between the straight portions of the secondconcave sliding surfaces 536 a, 536 b and/or equal to an outer radius ofthe drive puck 570.

The first housing section 530 a can be manufactured, for example, usinga lathe or screw machine from a piece of bar stock. The bar stock can bemade of any suitable material including steels and aluminum, includingthose listed above. The lathe or screw machine can rotate and feed thebar stock into contact with a die or cutting head and shape the outercasing 533 and/or cut out the central cavity 534. The upper face 531 acan also be shaped (e.g., rounded or cut in a conical manner to allowfor rotation of the drive ball 550). As illustrated in FIGS. 34B-34C, tocut the first groove 535 a a first cutting tool (e.g., a rounded endmill 505, drill bit, or other) can cut into the first end 533 a of thecasing 533 (either before or after machining out the central cavity 534)and cut towards the second end 533 b. Movement of the first cutting toolin a straight line can form the straight portion 536 c. The toroidalsurface 536 e can be formed by a rounded end of the first cutting tool.The cutting tool can be controlled by a computerized or manual millingmachine. This process can be repeated to cut the second groove 535 b.

In another option, as illustrated in FIGS. 34D-34E, the first cuttinginstrument can have an outer toroidal-shaped cutting or grinding surface506. This first cutting instrument can cut both the first and secondgrooves 535 a, 535 b. This first cutting instrument can be movedlinearly to straight cut portions 536 c, 536 d. Outer curvature of thecutting or grinding surface can form the first and second toroidalsurfaces 536 e, 536 f.

In the joint 500, the first and second lips 538 a, 538 b can be machinedinto the casing 533. In some embodiments, the first and second lips 538a, 538 b can be machined using the same cutting tool for cutting thefirst and second grooves 535 a, 535 b. This configuration can facilitatemachining of the housing section 530 a in an efficient manner. Forexample, in some embodiments, the first and second grooves 535 a, 535 bcan be cut out of a billet by the cutting tool at or near the first end533 a. Material can be removed by the first cutting tool in asubstantially straight path to form the straight portions of the firstand second grooves 535 a, 535 b. The cutting tool can continue until itis adjacent to the second end 533 b. In some embodiments, curvature atthe end of the first cutting tool can form the radius of curvature ofthe first and second lips 538 a, 538 b. Alternatively, the first andsecond grooves 535 a, 535 b can be cut with a first cutting tool and thefirst and second lips 538 a, 538 b can be cut using a second cuttingtool or finishing tool. In other embodiments, the first and second lips538 a, 538 b can be formed by cold rolling the second end 533 b towardsthe centerline of the housing section 530 a.

This configuration of the first and second grooves 535 a, 535 b ishighly manufacturable in comparison to the other joints. In joint 300,for example, it can be time consuming and difficult to cut thecylindrical channel 335 and form equatorial lines with the first end 331of the housing 330. The process of cutting the channel 335 can be evenmore difficult where close tolerances are required for smooth sliding ofadjacent surfaces. In some embodiments of the first and second grooves535 a, 535 b, the tolerances do not have to be as tightly maintainedbecause there is less surface contact between the concave slidingsurfaces 536 a, 536 b and the drive puck 570 than between the first andsecond channel surfaces 335 a, 335 b and the drive puck 370 of joint300.

The second housing section 530 b of the housing 530 can include a firstend 539 a and a second end 539 b. The first end 539 a can be configuredto interface with the first end 533 a of the first housing section 530a. An interface 530 c between the first and second housing sections 530a, 530 b can couple together the first and second components. Theinterface 530 c can include a face 539 c. The face 539 c can be planeror any other shape such that it can interface with the first housingsection 530 a of the first end 533 a.

In some embodiments, the interface 530 c can be a weld (e.g.,conventional welding techniques, laser beam welding, magnetic pulsewelding, or friction stir welding). In other embodiments, the interfacecan be mechanical couplings (e.g., screws, tongue and groove, orinterference fittings). In some embodiments, the interface 530 c is anelectron beam weld. An electron weld can be advantageous because itgenerates low heat in coupling together the first and second housingsections 530 a, 530 b. This can be particularly advantageous where heatexpansion or distortion of the housing 530 a can affect the tolerancesof the concave sliding surfaces 536 a, 536 b. For example, thetolerances of the concave sliding surfaces 536 a, 536 b can be on theorder of a few thousands of an inch. Significant deviation from withinthe tolerances (i.e., heat distortion from conventional welding) canprevent the drive puck 570 from rotating freely within the first andsecond grooves 535 a, 535 b.

The second housing section 530 b can include the second aperture 532 a.The second aperture 532 a can be disposed in the second end 538 b, 539 bof the second housing section 530 b. The second aperture 532 a can beconfigured for receiving the second shaft. For example, receiving 533 acan further include splines or a set screw disposed in the secondhousing section 530 b to secure the second shaft within the secondaperture 532 a.

In some embodiments, the central cavity 534 can extend all the waythrough both the first and second housing sections 530 a, 530 b. Thisconfiguration can allow for a lubricant to be inserted within thecentral cavity 534 from either end of the housing 530 and coat thesliding surfaces of the joint 500. In some embodiments, the centralcavity 534 can allow for the lubricant to flow through the housing 530in a continuous or intermittent manner. In some embodiments, the centralcavity 534 can thus provide advantages of facilitating the lubricationand/or cleaning of the joint 500 without the need to disassemble thecomponents of the joint 500.

The drive puck 570, shown in detail in FIGS. 36A-D, can include a firstwing 571 a and a second wing 571 b and an inner slot 573. An outerperiphery 572 a of the drive puck 570 can be circular about a centralaxis 572 b or when viewed from the top (as in FIG. 27B). A connectingregion 574 can connect the first and second wings 571 a, 571 b.

The drive puck 570 can include a convex sliding surface 572. Convexsliding surface 572 can be disposed around the outer periphery 572 a ofthe drive puck 570. The convex sliding surface 572 can be disposedacross the first and second wings 571 a, 571 b. In some embodiments, anoutermost portion of the outer periphery 572 has a radius of curvaturethat is circular. The convex sliding surface 572 can correspond to theshape of the concave sliding surfaces 536 a and 536 b of the first andsecond grooves 535 a, 535 b. For example, the convex sliding surface 572can be toroidal in shape. This allows for the drive puck to be slidinglyengaged within the first and second groove 535 a, 535 b. The radius ofthe outer periphery 572 a can be less than that of the groove distance535 c and greater than that of the lip distance 538 c. This ensures thatthe lips 538 a, 538 b retain the drive puck 570 within the grooves 535a, 535 b and within the housing 530. It also enables the drive puck 570to be rotatable and insertable within the grooves 535 a and 535 b.

The inner slot 573 can comprise a first inner side 573 a and a secondinner side 573 b. The first and second inner slides 573 a, 573 b caninclude substantially planer portions. The substantially planer portionscan be disposed on opposite sides of the inner slot 573. Thesubstantially planer portions can substantially parallel to each other.

An overhang 578 a can extend towards the center of the inner slot 573 atan outer end of the slot 573. Similarly, a second overhang portion 578 bcan extend towards a center line of the inner slot 573 from the secondinner side 573 b. The convex sliding surface 572 can extend across oneor both of the first and second overhang portions 578 a, 578 b. Thesefirst and second overhang portions 578 a, 578 b enable additionalrotation of the drive puck 570 within the housing 530 without coming outpast the lips 538 a, 538 b of the grooves 535 a, 535 b. The first andsecond overhang portions 578 a, 578 b can extend out from thesubstantially planer portions of the first and second inner slides 573a, 573 b of the slot 573. The first and second overhang portions 578 a,578 b can form an opening at the outer end of the slot 573 that isnarrower than the distance between the planar portions.

An aperture 577 is disposed through one or both of the first and secondwings 571 a, 571 b. The aperture 577 can extend through the central axis572 b of the drive puck 570, as illustrated in FIG. 36C. The aperture577 can extend through the planar portions of the inner sides 573 a, 573b.

The drive ball 550, shown in detail in FIGS. 37A-C can include a ballend 551 and a socket end 553. The ball end 551 and the socket end 553can be coupled together by a neck portion 555. The ball end 551 caninclude an outer surface 551 a. As explained further below, the ball end551 need not be spherical, but can be any desirable shape. The ball end551 can further include a shaft 557 disposed through the ball end 551.The ball end 551 can include one or more planar regions 558 a, 558 b.For example the ball end 511 can include first and second planar regions558 a, 558 b. The planar regions 558 a, 558 b can be disposed onopposite sides of the ball end 551 and can be substantially parallel toeach other. In some embodiments, the aperture 557 extends through theplanar regions 558 a, 558 b. The ball end 551 can further include atapped hole 559 for a set screw.

The socket end 553 can include a socket 553 a. In some embodiments, thesocket 553 a can be configured to be coupled with the first shaft of thejoint 500. For example the socket 553 a can include splines and a tapscrew for holding the output shaft within the socket 553 a. The socket553 a can be circular, square, rectangular, hexagonal, or any othersuitable shape. In other embodiments the socket end 553 is a maleconnector or any other type of connector coupling the drive ball 550with the second shaft. The outer surface of the socket end 553 can becylindrical or any other suitable shape.

A pin 580, shown in detail in FIGS. 38A-C, has a first end 581, a secondend 582. The pin 580 can be cylindrical, have a cylindrical shaftbetween the first and second ends 581, 582. Between the first and secondends 581, 582 can be a flattened portion 583. The flattened portion 583can be used as a place in which a set screw 590 can be inserted in tothe tapped hole 559 of the drive ball 550 and pressed against the pin580 to hold it with within the aperture 557.

To assembly the joint 500, the drive puck 570 can be inserted within thefirst housing section 530 a of the housing 530. The drive puck 570 canbe inserted into the first and second grooves 535 a, 535 b. The firstand second concave sliding surfaces 536 a, 536 b can be slidinglyengaged with the convex sliding surface 572 of the drive puck 570. Thedrive puck 570 can be rotatable within the first and second grooves 535a, 535 b.

The drive ball 550 can be coupled with the drive puck 570 by the pin580. The pin 580 can extend into the apertures 557 and 577 of the driveball 550 and drive puck 570, respectively. The pin can be secured withinthe apertures 557 and 577 by the set screw 590. The ball end 551 of thedrive ball 550 can be inserted into the central cavity 534 of the firsthousing section 530 a. The diameter of the ball end 551 must be smallerthan the opening of the central cavity 534 at the first end 531 of thehousing 530.

The second housing section 530 b can be assembled with the first housingsection 530 a. The first housing section 530 a is slid over the driveball 550 and interfaced with the second housing section 530 b. Forexample, the first and second housing sections 530 a, 530 b, can bewelded together or otherwise assembled at the interface 530 c. In someembodiments, this can be done with the drive puck 570 already insertedwithin the first housing section 530 a and coupled with the drive ball550.

A weld 530 d at the interface 530 c can extend into the outer casing533, as shown in FIGS. 41 and 42. Desirably, the weld 530 d and/orwelding process can avoid altering the dimensions of the grooves 535 a,535 b. Nonetheless, the altering of the grooves 535 a, 535 b at thefirst end 533 a of the housing 530 a can be acceptable where it does notinterfere with rotation of the drive puck 570. As noted above, electronbeam welding generates little heat and can create deep welds into amaterial to provide a firm coupling of the first and second housingsections 530 a, 530 b.

In some embodiments, the lips 538 a, 538 b can comprise a sharp orsquared corner to prevent the drive puck 570 from being removed from thegrooves 535 a, 535 b. In other embodiments, the toroidal surfaceportions 536 e, 536 f of the concave sliding surfaces 536 a, 536 b matchthe profile of the outer periphery 572 a of the drive puck 570. This canreduce friction and prolong service life of the drive puck and thehousing 530 by minimizing high-pressure contact areas between the drivepuck 570 and the grooves 535 a, 535 b.

In some embodiments, the central cavity 534 can comprise a tensioningmechanism 520. For example, the tensioning mechanism 520 can comprise aspring-loaded steel ball bearing, as illustrated in FIG. 41. The ballbearing can contact the outer periphery 572 a of the drive puck 570. Insome embodiments, the ball bearing can apply pressure to the outerperiphery 572 a to bias the drive puck 570 against the lips 538 a, 583b. This can reduce or minimize vibration and play in the joint 500during rotation of the assembly. Other tensioning mechanisms 520 caninclude, but are not limited to, a plastic or metal insert with thecentral cavity 534 and a coating of the planar surface 539 c of thesection housing section 530 a.

In some embodiments, the outer surface 551 a of the ball end 551 doesnot contact the inner surface 537 of the outer casing 533, asillustrated in FIGS. 42-43. A through-space 534 a can be disposedbetween the outer surface 551 a and the inner surface 537. Thisarrangement can facilitate application of the lubricant into the centralcavity 534. In embodiments where the central cavity 534 extends all theway through the housing 530, the through-space 534 a facilitates theflow of the lubricant past the drive puck 570 and the drive ball 550. Insome embodiments, the flow of the lubricant can be further facilitatedby a plurality of perforations extending all the way through the drivepuck 570 and/or the ball end 551 of the drive ball 550. The plurality ofperforations can extend in any direction or various directions tofacilitate the lubricant flow.

The manufacturing process 100 and 200, described above, can also beapplied to the components of the joint 500. For example, the housing530, including the first and second concave sliding surfaces 536, 536 band/or the drive puck 570 can be hardened or differentially hardened toprolong the service life of the joint 500. In some embodiments of thejoint 500, the vapor deposition, cryogenic hardening, case hardeningand/or shot peening described above can be applied to drive puck 570and/or the concave sliding surfaces 536, 536 b.

Sixth Embodiments of a Universal Joint

FIGS. 44-52 illustrate another embodiment of joint assembly 600. Likethe joint 400, the joint 600 can couple together a first shaft and asecond shaft (not shown) such that rotation of the first shaft about itslongitudinal axis transfers to rotation of the second shaft about itslongitudinal axis. For example, rotation of the first shaft can matchrotation of the second shaft. Joint 600 can include a housing 630 withfirst and second housing sections 630 a, 630 b. Each of the first andsecond housing sections 630 a, 630 b can include a structure similar tothe housing 630 described above. The manufacturing processes describedabove (including processes 100 and 200) can also be applied inconjunction with the sliding components and surfaces of the joint 600.

The joint 600 can include first and second drive pucks, 670 a, 670 b,first and second drive balls 650 a, 650 b and first and second pins 680a, 680 b. The first shaft can be coupled with the first drive ball 650a. The second shaft can be coupled with the second drive ball 650 b. Thefirst and second drive balls 650 a, 650 b can be coupled with first andsecond housing sections 630 a, 630 b of the housing 630 by the first andsecond drive pucks 670 a, 670 b, respectively. The first drive puck 670a can be coupled with the first housing section 630 a and rotate withrespect to the housing 630 in a first plane 601. The first drive ball650 a can be coupled with the first drive puck 670 a by the first pin680 a and thereby rotate with respect to the housing 630 in a secondplane 602. In this manner, the first drive ball 650 a can be rotatablewith respect to the housing 630 in both the first and second planes 601,602. In some embodiments, the first and second planes 601, 602 aresubstantially orthogonal to each other.

The second housing section 630 b can couple with the second drive puck670 b. The second drive puck 670 b can be rotatable with respect to thehousing 630 in a third plane 603. The second drive ball 650 b can becoupled with the second drive puck 670 b by the second pin 680 b andthereby rotate with respect to the housing 630 in a fourth plane 604. Insome embodiments, the third and fourth planes 603, 604 are substantiallyorthogonal to each other.

The first drive ball 650 a can be rotated to an angle 617 with respectto a longitudinal axis of the housing 630. Angle 617 can be maintainedduring rotation of the first shaft and joint 600 by sliding of the firstdrive ball 650 a and/or the first drive puck 670 a with respect to thehousing 630 within the first and/or second planes 601, 602,respectively. The second drive ball 650 b can be rotated to an angle 618with respect to a longitudinal axis of the housing 630. Angle 618 can bemaintained with respect to a longitudinal axis of the housing 630 duringrotation of the second shaft and joint 600 by rotation of the seconddrive ball 650 b and/or the second drive puck 670 b within the thirdand/or fourth planes 603, 604, respectively.

An angle 619 between the first and the second shafts can be adjustedbetween approximately 0° and a maximum of approximately 90° to 100°. Insome embodiments of the joint 600, it can be advantageous to createmaximum angle of 90°. The angle 619 across the joint 600 can bemaintained as the joint 600 rotates by corresponding rotations of thefirst and second drive pucks 670 a, 670 b within the first and thirdplanes 601, 603 and by rotation of the first and second drive balls 650a, 650 b within the second and fourth planes, 602, 604.

As explained above in relation to joint 400, in a joint with a singlerotational angle (e.g., joint 500), the rotational speed of the firstshaft coupled with the joint does not always match the rotational speedof the second shaft coupled with the joint, depending on the angle 517.The joint 600 can be used as a constant velocity joint provided theangles 617 and 618 are approximately equivalent and the first and thirdplanes 601, 603 and the second and fourth planes 602, 604 aresubstantially orthogonal to each other. This configuration provides theadvantages of substantially reducing vibration of the joint 600 duringrotation.

The first and second drive pucks 670 a, 670 b can have the samestructure as described above in relation to the drive puck 570. Thefirst and second drive balls 650 a, 650 b can have the same structure asdescribed above in relation to the drive ball 550. The first and seconddrive balls 650 a, 650 b can include first ends 651 a, 651 b, and secondends 653 a, 653 b, respectively. The first and second pins 680 a, 680 bcan have the same structure as described above in relation to pin 580.

As shown in FIGS. 47A-C, housing 630 can include a housing casing 633with the first and second housing sections 630 a, 630 b. The housingcasing 633 can be tubular in nature and an inner wall 637 of the housingcasing 633 can define an central cavity 634. In some embodiments, thecentral cavity 634 extends through the housing casing 633. In someembodiments, the second housing section 630 b can be configured to bemachined separately and coupled with the first housing section 630 a atan interface 630 c, such as by welding or mechanical fasteners, asdescribed above in connection with the housing 530.

Each of the first and second housing sections 630 a, 630 b can havesubstantially the same structural components as the first housingsection 530 a of the joint 500. In some embodiments, the first housingsection 530 a can be manufactured as a modular component that can becoupled with the second housing section 530 b as a part of the joint 500or it can be coupled with another modular housing section (e.g., housingsection 630 b) to form a part of the joint 600. The modular nature ofthe first housing section 630 a provides the advantages of reducing thenecessary inventory that a manufacturing needs on hand and reduces thecost and complexity of building parts for each of the joints 500 and600.

The first housing section 630 a can include first and second grooves 635a, 635 b. The first and second grooves 635 a, 635 b can be disposed onopposite sides of the central cavity 634. The first and second grooves635 a, 635 b can be disposed within the inner surface 637 of the housingcasing 633. The first and second grooves 635 a, 635 b can include firstand second concave sliding surfaces 636 a, 636 b, respectively. Thefirst and second concave sliding surfaces 636 a, 636 b can extend froman inner end 633 c to the outer end 633 a of the first housing section630 a.

The first housing section 630 a can include first and second lips 638 a,638 b. In some embodiments, the first and second lips 638 a, 638 b areat the outer end 633 a of the housing section 630 a. The first andsecond concave sliding surfaces 636 a, 636 b can extend at leastpartially across the lips 638 a, 638 b, respectfully. Where the concavesliding surfaces 636 a, 636 b cross the lips 638 a, 638 b, the concavesliding surfaces 636 a, 636 b can each compromise a circular radius ofcurvature that is circular or substantially circular and/or matches theshape of the drive puck 670 a. The second housing section 630 b can havethe same structure as the first housing section 630 a.

The joint 600 can be assembled by inserting an inner end 651 a of thefirst drive ball 650 a within an inner slot 673 a of the first drivepuck 670 a. The first drive puck 670 a can be pivotally coupled with theinner end 651 a with the first pin 680 a. In some embodiments a setscrew 690 can secure first pin 680 a in place through a hole 659 a. Thefirst drive puck 670 a can be inserted within the grooves 635 a, 635 b.An outer surface 672 a of the first drive puck 670 a can be slidinglyengaged with the concave sliding surfaces 636 a, 636 b. The first drivepuck 670 a can rotate about within the grooves 635 a, 635 b and withinthe first plane 601. The first drive ball 650 a can rotate about thefirst pin 680 a within the second plane 602.

The second drive ball 650 b can be assembled with an inner slot of thesecond drive puck 670 b and assembled therewith by the second pin 680 b.The second drive puck 670 b can be assembled within third and fourthgrooves 635 c, 635 d and rotate within the third plane 603. The seconddrive ball 650 b can rotate about the second pin 680 b and within thefourth plane 604. Once assembled the first and second drive balls 650 a,650 b can be pivoted to the angles, 617, 618, respectively, with respectto the housing 630.

In some embodiments, the central cavity 634 can comprise a tensioningmechanism (not shown). For example, the tensioning mechanism cancomprise a plastic or metal insert within the central cavity 634. As aninsert, the tensioning mechanism can comprise two grooves on oppositesides of the insert (either parallel or crossways at an angle to eachother, depending on the orientation of the first and second drive pucks670 a, 670 b) that contact the outer surfaces of the first and seconddrive pucks 670 a, 670 b. In some embodiments, the insert can applypressure to the outer surfaces to bias the first and second drive pucks670 a, 670 b against the respective lips 638 a-b, 638 c-d of the firstand second housing sections 630 a, 630 b. For example, the insert caninclude one or more springs to apply pressure against the first andsecond drive pucks 670 a, 670 b. This can reduce or minimize vibrationand play in the joint 600 during rotation and/or movement of theassembly.

In some embodiments, the central cavity 634 can extend all the waythrough both the first and second housing sections 630 a, 630 b. Thisconfiguration can allow for a lubricant to be inserted within thecentral cavity 634 from either end of the housing 630 and coat thesliding surfaces of the joint 600. In some embodiments, the lubricantcan cool the components of the joint 600. In some embodiments, thecentral cavity 634 can thus provide advantages of facilitating thelubrication and/or cleaning of the joint 600 without the need todisassemble the components of the joint 600.

In some embodiments, the central cavity 634 can allow for the lubricantto flow through the housing 630 in a continuous or intermittent manner.A through-space, similar to through space 534 a can be disposed betweenthe drive balls 650 a, 650 b and the inner surface 637. This arrangementcan facilitate application of the lubricant into and through the centralcavity 634. In some embodiments, the flow of the lubricant can befurther facilitated by a plurality of perforations extending all the waythrough either or both of the first and second drive pucks 670 a, 670 band/or the first and second drive balls 650 a, 650 b. The plurality ofperforations can extend in any direction or various directions tofacilitate the lubricant flow.

Seventh Embodiments of a Universal Joint

The structures of either of the joints 400 or 600 can be used to form ajoint, socket wrench attachment 700. The attachment 700 can be used inconjunction with a standard or customized socket wrench handle to enablethe removal and/or installation of various fasteners (e.g., bolts andnuts) at an angle. This can provide access to locations and areas thatwere previously inaccessible to socket wrenches and/or facilitate readyaccess to these locations in a more straightforward manner. For example,the attachment 700 can facilitate the installation or tightening of abolt in an automobile engine without requiring disassembly ofsurrounding components.

As shown in FIGS. 53-56 and described herein, the attachment 700 caninclude a housing 730, first and second connectors 750 a, 750 b, firstand second drive pucks 770 a, 770 b, and first and second pins 780 a,780 b. The first and second connectors 750 a, 750 b can be coupled withthe first and second drive pucks, 770 a, 770 b by the first and secondpins 780 a, 780 b, respectively. The first and second drive pucks 770 a,770 b can be coupled with first and second housing halves 730 a, 730 bwithin grooves 735 a, 735 b, respectively. The first and second pins 780a, 780 b can be retained within apertures of the first and secondconnectors 750 a, 750 b by first and second set screws 791 a, 791 b,respectively. The first connector 750 a can rotate about the first drivepuck 770 a within the grooves 735 a and about the pin 780 a. The secondconnector 750 b can rotate about the second drive puck 770 b within thegrooves 735 b and about the pin 780 b. FIG. 56 shows first and secondoverhang portions 778 a, 778 b in the first drive puck 770 a. FIG. 56shows lips 738 a, 738 b aligned with grooves 735 a, 735 b, respectively.FIG. 56 shows toroidal surface portions 736 a, 736 b on the lips 738 a,738 b.

The housing 730 can further include a sleeve 741. The sleeve 741 can bedisposed over a least a portion of the housing 730. The sleeve 741 canbe a thin-walled cylinder or plastic, metal, or any suitable material.The sleeve 741 can be rotatable about approximately the longitudinalaxis of the housing 730. In some embodiments, the sleeve 741 isslidingly engaged with an outer cylindrical surface 731 of the housing730. In some embodiments, the sleeve 741 can include a grip surface.

The sleeve 741 can be maintained in place on the housing 730 by firstand second retaining rings 742, 743. The retaining rings 742, 743 caneach be disposed within corresponding slots 744 a, 744 b on the housing730. The sleeve 741 can be removed from the housing 730 by removing oneor more of the retaining rings 742, 743, such as for maintenance orreplacement.

The first connecter 750 a can include a socket aperture 753 a. Thesocket aperture 753 a can be sized to couple with a standard socketdriver. For example, the socket aperture 753 a can be sized to couplewith any standard or custom drives for socket wrenches including squareand splined drives in the following sizes: ¼″, ⅜″, ⅝″, ½″, ¾″, 1″, 1½″,2½″, and 3½″ or standard metric drives. The second connector 750 b cancomprise a socket driver or drive end 753 b. The drive end 753 b caninclude a drive in any standard or custom size, including those listedabove. In some embodiments, the drive end 753 b can include a frictionball or locking pin to secure the drive end 753 b with a socket,extension or other wrench accessory.

The attachment 700 can be operated by a user by coupling the socketaperture 753 a with a wrench handle in the conventional manner. A socketin the desired size can be coupled on the drive 753 b. The user canmaneuver the socket into the desired position (e.g., onto the head of abolt or nut) by rotating the first and second connectors 750 a, 750 band first and second drive pucks 770 a, 770 b of the attachment 700. Inthe desired position, the user can hold the sleeve 741 in one hand toprovide a degree of stability to the attachment 700. This stability canaid in holding the attachment 700 at desired angle and/or enable theuser to maintain the socket on the head of the bolt. The user's otherhand can be used to rotate the wrench handle in the desired direction.The attachment 700 can transmit rotation from the wrench handle to thesocket and head at the desired angle. The housing 730 of the attachment700 can rotate with respect to the user's hand within the sleeve 741.

In some embodiments, an insert (not shown) can be placed within thehousing 730 and contact outer surfaces of the first and second drivepucks 770 a, 770 b and/or the inner ends of the first and secondconnectors 750 a, 750 b. The insert can be made from a plastic andprovide friction against the rotation of the first and second drivepucks 770 a, 770 b and the first and second connectors 750 a, 750 bwithin the housing 730. In this manner, the attachment 700 can be madepositionable. This can facilitate the use of the attachment 700 whileavoiding unwanted motion from the components thereof.

Additional Embodiments of a Universal Joint

FIGS. 57-58 illustrate another embodiment of a joint 800, similar to thejoints described above. Joint 800 can comprise a housing 830, drive puck870, drive ball 850, pin 880 and a cap ring 890. The housing 830 cancomprise a first end 831 and a second end 832. In some embodiments, thehousing 830 can comprise first and second housing components 830 a and830 b coupled together at interface 830 c. The first and second housingcomponents 830 a, 830 b can be coupled together by welding or othermechanical means (e.g. electron beam welded, mechanical fasteners, orother). In some implementations (not shown), the first housing component830 a can be identical to the second housing component 803 b to form a90-degree joint similar to joint 400.

The housing 830 can comprise an inner cavity 834 and first and secondchannels 835 a, 835 b within an inner wall 837 of the inner cavity 834.The first and second channels 835 a, 835 b can be toroidal surfaces. Insome embodiments, the first and second channels 835 a, 835 b can be asingle channels. Alternatively, the housing 830 can include first andsecond grooves, similar to the first and second grooves 535 a, 535 b.

The cap ring 890 can comprise first and second contact surfaces 895 a,895 b. The first and second contact surfaces 895 a, 895 b can betoroidal surfaces, similar to the toroidal surface portions 536 e, 536 fof the first and second grooves 535 a, 535 b. The cap ring 890 cancouple with the first end 831 of the housing 830. In some embodiments,the first end 831 and the cap ring 830 can comprise correspondingposts/recesses 898 to align the cap ring 890 with the first end 831. Insome embodiments, the first end 831 is welded (e.g., electron beam,friction stir, or otherwise welded) with the cap ring 890. In someembodiments, the first end 831 and the cap ring 890 include an enlargedouter edge to accommodate the welding without excess heat and/ordeformation caused by the welding deforming the housing 830 (e.g., theinner wall 837, first or second channel 835 a, 835 b) or cap ring 890,which deformation would likely render the joint 800 inoperable.

The joint 800 can be assembled by coupling a first end 851 of the driveball 850 with the of the drive puck 870 with the pin 880. The drive puck870 can be inserted within the first and second channels 835 a, 835 b ofthe housing 830 and rotatable therein. The cap ring 890 can couple withthe first end 831 to secure the drive puck 870 within the housing 830.The cap ring 890 can be mechanically coupled with the first end 831 inany suitable manner. In some embodiments, an outer surface 851 a of thefirst end 851 of the drive ball 850 does not contact the inner wall 837of the housing 830 and a through-space can be disposed therebetween.

A second end 853 of the drive ball can be rotatable with respect to thehousing 830 about the drive puck 870 and the first end 851 of the driveball 850. A first shaft can be coupled with the second end 832 of thehousing 830 and a second shaft can be coupled with the second end 853 ofthe drive ball 850.

FIGS. 59-60 illustrate another embodiment of a joint 900, similar to thejoints described above. Joint 900 can comprise a housing 930, drive puck970, drive ball 950, pin 980 and a cap ring 990. The housing cancomprise a first end 931 and a second end 932. The housing 930 cancomprise an inner cavity 934 and first and second channels 935 a, 935 bwithin an inner wall 937 of the inner cavity 934. The first and secondchannels 935 a, 935 b can be similar to the first and second channels335 a, 335 b. The inner wall 937 can also comprise first and secondconcave spherical surfaces 936 a, 936 b, similar to the first and secondspherical surfaces 336 a, 336 b. Alternatively, the housing 830 caninclude first and second grooves instead of the first and secondchannels 935 a, 935 b, similar to the first and second grooves 535 a,535 b.

The cap ring 990 can comprise third and fourth channels 995 a, 995 b.The cap ring 990 can couple with the first end 931 of the housing 930.The cap ring can comprise third and fourth concave spherical surfaces996 a, 996 b. In some embodiments, the first end 931 and the cap ring990 can comprise corresponding posts/recesses 998 to align the cap ring990 with the first end 931.

The first and second channels 935 a, 935 b can each comprise a centralcylindrical portion 935 c and outer rounded portions 935 e, 935 f.Similarly, an outer contact surface 972 of the drive puck 970 cancorrespondingly comprise a central cylindrical portion 975 c and outerrounded portions 975 e, 975 f. The outer contact surface 972 canslidingly engage within the first and second channels 935 a, 935 b. Thethird and fourth channels 995 a, 995 b of the cap ring 990 can also eachcomprise a central cylindrical portion 995 c and outer rounded portions995 e, 995 f. An outer spherical surface 951 a of the drive ball 950 canslidingly engage with the first through fourth concave sphericalsurfaces 936 a, 936 b, 996 a, 996 b.

The joint 900 can be assembled by coupling a first end 951 of the driveball 950 with the of the drive puck 970 with the pin 980. The drive puck970 can be inserted within the first and second channels 935 a, 935 b ofthe housing 930 and rotatable therein. The cap ring 990 can couple withthe first end 931 to secure the drive puck 970 within the housing 930.The cap ring 990 can be mechanically coupled with the first end 931 inany suitable manner. In some embodiments, the first end 931 is welded(e.g., electron beam, friction stir, or otherwise welded) with the capring 990. In some embodiments, the first end 931 and the cap ring 990include an enlarged outer edge to accommodate the welding without excessheat and/or deformation caused by the welding deforming the housing 930(e.g., first and second channels 935 a, 935 b and/or the first andsecond concave spherical surfaces 936 a, 936 b) or cap ring 990.

In some implementations, a thickness the outer edge of the housing 930at the first end 931 is at least 16 mm. The thickness can be within therange of 10 mm to 25 mm or greater. In some implementations, the firstend 931 is welded in a lateral welding pattern where only the sides ofthe first end 931 and sides cap ring 990 that do not include thechannels 935 a, 935 b, 995 a, 995 b (e.g., at posts/recesses 998, asillustrated in FIG. 60) are welded. Similarly, the cap rings of thejoint assemblies 10, 10 a, 300, and 400 can include the enlarged outeredge (and/or the lateral welding pattern) and be welded to form both 45and 90 degree joints. In some implementations, none of the jointassemblies 10, 10 a, 300, and 400, 500, 600, 700, 800 or 900 includemechanical fasteners and are instead assembled using any suitablewelding techniques.

A second end 953 of the drive ball can be rotatable with respect to thehousing 930 about the drive puck 970 and the first end 951 of the driveball 950. A first shaft can be coupled with the second end 932 of thehousing 930 and a second shaft can be coupled with the second end 953 ofthe drive ball 950.

FIG. 61 illustrates the joint 600 coupled within a carrier bearingassembly 1000. The carrier bearing assembly 1000 can include an outercasing 1002 and bearings 1004. The bearings 1004 can be any type ofbearing (e.g., ball, needle or other) and contact either directly orindirectly the housing 630. The carrier bearing assembly 1000 can couplewith the housing 630 by one or more retainer rings 1006 that couplewithin a slot on the housing 630. The joint 600 can be rotatable withinthe outer casing 1002. The outer casing 1002 can be rigidly coupled withany structure. For example, the outer casing can be rigidly coupled witha frame member of an automobile. The carrier bearing assembly 1000 canallow for the joint 600 to couple with first and second shafts 1010,1012 with rotation form the first shaft 1010 being transmitted to thesecond shaft 1012 through the joint 600. The first and second shafts1010, 1012 can be maintained at an angle 1014. The angle 1014 can be upto approximately 90-100°. In some embodiments, the angle 1014 can bemaintained or at the joint 600 rotates within the outer casing 1002about the bearings 1004.

FIG. 62 illustrates an exploded view of another embodiment of a joint.The joint 1100 is similar in construction to the joint 500 as shown inFIGS. 31-43. Similar components have been given similar element calloutsand have been updated to the 1100 series. The joint 1100 can include ahousing base 1130 b and a housing 1130 a. The housing 1130 a can includeinternal grooves similar to the grooves 535 described above. The housingcomponent 1138 can be coupled with the base component 1130 b. In someimplementations, one or more pins 1131 a and 1131 b can be used betweenthe base component 1130 b and the housing 1130 a to provide alignment tothe two pieces before they are coupled together. The base component 1130b and the housing 1130 a can be coupled in a permanent fashion using,for example, electron beam welding or other welding or suitable means. Adrive puck 1170 can be received within the grooves within the firsthousing component 1130 a. A drive shaft 1150 can be pivotally coupledwith the drive puck 1170 by a pin 1180. An outer end of the drive shaft1150 can be a male socket attachment, as described above in relation tothe socket wrench attachment shown in FIGS. 53-56. The base component1130 b can have a recess in it that is a female socket attachment. Inthis manner, the joint 1100 can be used in conjunction with a socketsystem or socket wrench. A male socket attachment, such as coupled witha wrench or impact drill, can be coupled with the base 1130 at itsrecess and a socket tool attachment (e.g., socket) can be coupled withthe outer end of the drive shaft 1150. The function of the joint 1100can be similar to that of the joint 500 and other joints describedherein.

The joint 1100 can also include an insert 1120. In some implementations,the insert 1120 can be donut-shaped and/or received within a recessportion 1121 within the base component 1130 b. The insert 1120 is usedto fill space between a ball end of the drive shaft 1150 and the basecomponent 1130 b. In certain implementations, the insert 1120 reducesmovement and/or play of the drive shaft 1150 and/or drive puck 1170within the housing 1130 a. The insert 1120 can push the assembly of thedrive puck 1170 and the drive shaft 1150 towards lips within the housing1130 as described above (e.g., FIG. 41). Materials for the insert 1120can include plastics and polymers, carbon fiber cloth, nylon fibercloth, or other fibers or ceramic abrasive materials. In certainimplementations, the insert 1120 can reduce noise of the joint 1100(i.e., from rotation of the joint). Although shown in a donut shape, theinsert 1120 can have any suitable form factor for filling spaced withinthe housing 1130 a.

With reference to FIG. 63, the joint 1210 is constructed similar to thejoint 10 and the joint 300 described above. Elemental callouts of thejoint 1200 have been updated with similar components having numbers andbeing updated to the 1200 series numerals. The joint 1200 can include afirst housing 1212, a second housing 1224, and cap ring 1226. The firstand second housings 1212, 1224 can be coupled together with mechanicalfasteners such as that all three of these components can be coupledtogether. For example, one or more bolts can be inserted around an outerperiphery of the components. The second housing 1224 can include acylindrical channel and one or more spherical hemispheres for receivinga drive puck 1270 and a drive ball 1222. The drive puck 1270 can rotatewithin the channel of the second housing 1224. The drive ball 1222 canbe pivotally coupled with the drive puck 1270 by first and second pins1256, 1258 that can be inserted through apertures of the drive puck 1270and coupled with the drive ball 1222. In another implementation, a pincan be received through the drive puck 1270 and the drive ball 1222. Aninner end 1214 a of a shaft 1214 can be received within a recess 122 aof the drive ball 1222. The function of the joint 1200 can be similar tothat of the joints 10 and 300 and other joints described herein.

While any suitable materials can be used to construct the components ofthe joint 1200 (e.g., steel aluminum or other metals), in oneimplementation, the joint 1200 uses steel for the construction of thefirst housing 1212 and the cap ring 1226. In some implementations, thesecond housing 1224 can be constructed out of a different material thansteel. For example, by using an aluminum material for the second housing1224, the advantageous heat properties of aluminum can be utilized inthe joint 1200. Aluminum can have up to four times the thermalconductivity (approximately 205 W/MA) than that of the thermalconductivity of steel (approximately 50.2 W/MA). Thus, during high speedoperation of the joint 1200, heat generated by movement of the puck anddrive ball within the second housing 1224 can be dissipated very quicklyas compared to heat generated in the first housing 1212 or the cap ring1226 (or compared with a steel second housing 1224). Any combination ofmaterials having either the same or different thermal conductivity canbe substituted for the steel and aluminum components used variously inthe first housing 1212, second housing 1224, and the cap ring 1226. Forexample, other materials, such as steel, stainless steel, aluminum,iron, brass, tungsten, tool steel and/or the like can be used for thesecond housing 1224, first housing 1212 and/or cap ring 1226.

Although specific embodiments have been described above, the aboveembodiments are not intended to limit the scope of the presentdisclosure, even where only a single embodiment is described withrespect to a particular feature. Examples of features provided in thedisclosure are intended to be illustrative rather than restrictiveunless stated otherwise. The above description is intended to cover suchalternatives, modifications, and equivalents as would be apparent to aperson skilled in the art having the benefit of this disclosure.

The scope of the present disclosure includes any feature or combinationof features disclosed herein (either explicitly or implicitly), or anygeneralization thereof, whether or not it mitigates any or all of theproblems addressed herein. Accordingly, new claims may be formulatedduring prosecution of this application (or an application claimingpriority thereto) to any such combination of features. In particular,with reference to the appended claims, features from dependent claimsmay be combined with those of the independent claims and features fromrespective independent claims may be combined in any appropriate mannerand not merely in the specific combinations enumerated in the appendedclaims.

What is claimed is:
 1. A mechanical joint for transferring rotationalmotion from a first shaft to a second shaft, comprising: a housingcomprising an outer casing, a central cavity, a first end and a secondend; a first groove comprising a first straight-cut contact surface, asecond groove comprising a second straight-cut contact surface, thefirst and second grooves disposed on opposite sides of the centralcavity; a first lip comprising a third contact surface at the first endof the housing, the first lip aligned with the first groove; a secondlip comprising a fourth contact surface at the first end of the housing,the second lip aligned with the second groove; a drive puck comprising acircular outer perimeter, an outer contact surface, and an inner slot; adrive shaft comprising a first end and a second end, the first endpivotably coupled with the drive puck by a pin, the second endconfigured to couple with the first shaft; wherein the drive puck isdisposed within the first and second grooves, the outer contact surfaceslidingly engaged with the first and second straight-cut contactsurfaces of the first and second grooves, respectively, the drive puckmaintained within the first and second grooves at the first end of thehousing by the third and fourth contact surfaces of the first and secondlips; and wherein the drive puck rotates within the first and secondgrooves in a first plane and the drive shaft rotates about the pin in asecond plane, the first plane being orthogonal to the second plane. 2.The mechanical joint for transferring rotational motion of claim 1,wherein: the housing comprises a first housing component coupled with asecond housing component; the first housing component comprises an outerend and an inner end, the first and second grooves, and the first end ofthe housing; the second housing component comprises an outer end and aninner end, the second end of the housing, and an aperture for couplingwith the second shaft at the outer end; and the inner ends of the firstand second housing components are welded together to form the housingwith the drive puck disposed within the first and second grooves.
 3. Themechanical joint for transferring rotational motion of claim 2, furthercomprising: a recess on a face of the inner end of the second housing;and an insert disposed within the recess; wherein the insert engageswith the drive puck to reduce movement of the drive puck within thefirst and second grooves.
 4. The mechanical joint for transferringrotational motion of claim 1, wherein the second end of the drive shaftis a standard socket drive and the second end of the housing comprises astandard socket aperture.
 5. The mechanical joint for transferringrotational motion of claim 1, wherein: the inner slot of the drive puckincludes a first flat side on a first wing and a second flat side on asecond wing, the first flat side being substantially parallel to thesecond flat side, the first aperture extending through the first andsecond flat sides; the first end of the drive shaft includes a firstplanar portion and a second planar portion, the first and second planarportions disposed on opposite sides of the first end of the drive shaft,the second aperture extending through the first and second planarportions; and the first and second planar portions slidingly engagedwith the first and second flat sides of the inner slot, respectively. 6.The mechanical joint for transferring rotational motion of claim 5,further comprising: a first overhang portion at an upper opening of theinner slot, the outer contact surface of the first wing of the drivepuck extending onto the first overhang portion; a second overhangportion at the upper opening of the inner slot, the outer contactsurface of the second wing of the drive puck extending onto the secondoverhang portion; and a central portion of the drive shaft locatedbetween the first and second ends of the drive shaft; wherein thecentral portion is passable between the first and second overhangportions at the upper opening of the inner slot.
 7. The mechanical jointfor transferring rotational motion of claim 1, wherein: the housingcomprises a first housing component coupled with a second housingcomponent, the first housing component comprising an outer end and aninner end, the first and second grooves, and the first end of thehousing; the second housing component comprises a third groove having afifth contact surface, a fourth groove having a sixth contact surface,the third and fourth grooves disposed on opposite sides of the centralcavity; a third lip comprises a seventh contact surface at the secondend of the housing, the third lip aligned with the third groove; afourth lip comprises an eighth contact surface at the second end of thehousing, the fourth lip aligned with the fourth groove; a second drivepuck comprises a circular outer perimeter, an outer contact surface, andan inner slot; a second drive shaft comprises a first end and a secondend, the first end pivotably couples with the second drive puck by asecond pin, the second end configured to couple with the second shaft;the second drive puck is disposed within the third and fourth groovesand maintained therein by the third and fourth lips; and the inner endof the first housing component is welded to the inner end of the secondhousing component.
 8. The mechanical joint for transferring rotationalmotion of claim 7, further comprising: a rotational sleeve, therotational sleeve disposed around the housing, the rotational sleeveslidingly engaged with a cylindrical outer casing of the housing suchthat the rotational sleeve can rotate about a longitudinal axis of thehousing; wherein a user can rotate the housing while grasping therotational sleeve and the second end of the drive shaft is a socketdriver and the second end of the second drive shaft comprises a socketaperture.
 9. The mechanical joint for transferring rotational motion ofclaim 7, further comprising: a through-path defining a lubricant spaceextending from the outer end of the first housing component to the outerend of the second housing component through the central cavity; whereina lubricant can flow through the central cavity and lubricate the drivepucks and the grooves.
 10. The mechanical joint for transferringrotational motion of claim 7, wherein the drive puck rotates in a firstplane and the second drive puck rotates in a second plane, the first andsecond planes being orthogonal.
 11. The mechanical joint fortransferring rotational motion of claim 1, wherein the outer contactsurface of the drive puck is toroidal and the first and second lips eachcomprise a toroidal contact surface.
 12. The mechanical joint fortransferring rotational motion of claim 1, wherein the first and secondcontact surfaces of the first and second grooves, respectively, arecylindrical and convex.
 13. A mechanical joint for transferringrotational motion from a first shaft to a second shaft, comprising: ahousing, the housing having a first open end and a second end; a firstdrive puck disposed in the first open end, the first drive puckcomprising a first wing, a second wing, an inner slot, and a circularouter perimeter having an outer contact surface; a first drive shaftcoupled with the first drive puck, the first drive shaft comprising afirst end and a second end, the first end pivotably coupled within theinner slot of the first drive puck by a first pin, the second endconfigured to couple with the first shaft; wherein the first and secondwings of the first drive puck each comprise an inner planar surfaceforming the inner slot, and the first end of the first drive shaftcomprises first and second opposite planar surfaces slidingly engagedwith the inner planar surfaces, respectively; wherein the first driveshaft rotates in a first plane with respect to the housing about thefirst pin and rotates in a second plane with respect to the housing onthe first puck; first and second straight-cut grooves disposed in thefirst open end of the housing on opposite sides of a central cavity; andfirst and second lips at the first open end, the first and second lipsaligned with the first and second straight-cut grooves, respectively;wherein the drive puck is slidingly engaged within the first and secondstraight-cut grooves and maintained within the first and secondstraight-cut grooves at the first open end of the housing by the firstand second lips.
 14. The mechanical joint of claim 13, furthercomprising: a first channel disposed in the first open end; and a firstcap ring comprising a central opening and first and second channelsegments, the first cap ring coupled with the first end of the housingwith the first drive puck disposed within the first channel and thefirst and second channel segments, the outer contact surface of thefirst drive puck slidingly engaged with a bottom surface of the firstchannel, and the second end of the first drive shaft extending throughthe central opening of the first cap ring.
 15. The mechanical joint ofclaim 14, further comprising: a second channel disposed in the secondend of the housing; a second drive puck disposed in the second channel;a second drive shaft coupled with the second drive puck, the seconddrive shaft comprising a first end and a second end, the first endpivotably coupled within an inner slot of the second drive puck by asecond pin, the second end configured to couple with the second shaft; asecond cap ring comprising a central opening and first and secondchannel segments, the second cap ring welded with the second end of thehousing with the second drive puck disposed within the second channeland the first and second channel segments of the second cap ring, andthe second end of the second drive shaft extending through the centralopening of the second cap ring; wherein the second drive shaft rotateswith respect to the housing about the second pin and also rotates withrespect to the housing on the second puck.
 16. The mechanical joint ofclaim 14, wherein a hardness of the bottom surface of the channel is atleast 2 HRC above a hardness of the outer contact surface of the drivepuck.
 17. The mechanical joint of claim 14, wherein the housing iscryogenically hardened below −184° C. for at least 12 hours.
 18. Themechanical joint of claim 14, wherein a physical vapor depositioncoating is applied to the outer contact surface of the drive puck. 19.The mechanical joint of claim 14, wherein the first cap ring is electronbeam welded with the first end of the housing.
 20. The mechanical jointof claim 14, wherein the housing comprises a first housing componentmade of steel and a second housing component made of aluminum, the capring and the first housing component are mechanically coupled with thesecond housing component, the second housing component comprising thechannel.
 21. The mechanical joint of claim 13, further comprising thirdand fourth straight-cut grooves disposed in the second end of thehousing on opposite sides of the central cavity; and third and fourthlips at the second end of the housing, the third and fourth lips alignedwith the third and fourth grooves, respectively; wherein the seconddrive puck is slidingly engaged within the third and fourth straight-cutgrooves and maintained within the third and fourth straight-cut groovesat the second end of the housing by the third and fourth lips.